Citroën CX 25 mekartips -> Insprutningssystemet -> Går inte som den skall
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     uppdaterad 2007-11-15
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CX 25 GTi

Går inte som den skall: Till toppen av sidan
Motor lugger under kjøring(fusker):   Eirik J (N) 2006-01-05:
NÅ ER JEG LEI! GODE RÅD MOTTAS MED STOR TAKK. Gjelder min CX TGi -91. Motoren starter lett. Går flott på tomgang. Akselererer godt. Fungere helt topp så lenge man har antydning til gasspådrag. Problemet oppstår når man slipper gassen ørlite, eller kjører med jevn hastighet i svak nedoverbakke. Da man har mellomgass der motoren verken bremser eller øker farten. Da kommer en svak lugging/ujevn gange. Har lett etter årsaken til dette i flere dager. Har lest ALLT om emnet på Akuten. Tydeligvis noe av det mest vanlige problemet på CX. MASSE folk som har hatt dette som problem. Problemet er at folk ikke kommer med rapport når de finner feilen. Hjelp skal de ha, men etterpå gir de seg f.... Er jo synd for de som leser gamle tråder for å finne ut av noe. Nåjah....nok om det.
   På meg virker det som "magerfusk", altså at motoren går med for mager blanding ved lite og ingen gasspådrag. Tennpluggene tyder også på det, da de helt ufarget av forbrenningen. (Skulle helst hatt en litt lysebrun farge på dem). Siden TGi'er har en kontrollkontakt for bensinblandingen, har jeg tatt utganspunkt i den. Når man måler på pluggen skal det være 6,3 volt i følge manualen. Der var det 3 volt. Et stort problem er at manualen ikke sier noe om hva dette er. Altså, hva er forholdene hvis verdien er under 6,3 eller over. Mager eller fet?
   En annen ting jeg har lett etter er falskluft. Har lett i flere timer. Prøvd masse. Sjekket med startgass osv. Finner ingen falskluft. Har prøvd å justere på fjæra i luftmengemåleren. Justert 3 knepp både en og andre veien. Nesten ingen forskjell. Bortsett fra på måleverdien på kontrollstikket. Når fjæren strammes klarer jeg å justere på CO-skruen slik at jeg får 6,3 volt på kontrollstikket. Men bilen går akkurat likens som før Har også prøvd å slakke på fjære. Da ble bilen litt værre. Har nå stillt fjæra tilbake til fabrikkstillingen. Har da 3 volt på kontrollstikket. Skal være 6,3v. Men aner ikke hva det betyr at spenningen er lavere enn det skal være. Dette er mangelfullt i manualen.
   Det er nye tennplugger, nytt bensinfilter og nyvasket luftfilter.
   Fant korrosjon på kontakten til luftmengemåleren. Fikset det. Ingen forbedring. Fant eksoslekkasje fra en sveis på grenrøret. Sveiset det, ingen forskjell. Demontert luftmengemåleren og renset/rengjort den. Ingen forskjell. Demontert lambdasonde og blåst den ren, ingen forskjell....... AARRGGHHH!!! Er det ikke sommer snart så jeg kan kjøre DS??
   Det jeg nå har lyst å prøve er å skifte lambdasonde, men den er dyr. Og sure penger er det hvis det ikke blir i orden. Er dessuten skeptisk til luftmengdemåleren.... Driver å rydder i garasjen. For en liten tid siden kastet jeg en slik sonde jeg har hatt liggende i 8 år.... Man må ALDRI kaste noe......
  Anders (DK): Standard problemet er lige præcis falsk luft. Har motoren i din TGI de velkendte 4 luftslanger til indsugningen? Det er faktisk ALTID her problemet findes. Enten er slangerne møre og sprækkede - eller også er de løs på studserne.
   Det passer ikke at lambda sonden er skrækkelig dyr. Køb en standard lambda sonde hos Biltema til 199,- Dkr. Lambdasonden er ikke model/motor specifik, men en generisk sensor som altid giver samme signal ved samme iltmængde i udstødningen. Monterings hul med gevind er standardiseret som på et tændrør. Citroen/Peugeot anvender samme type til alle modeller & årgange. Det er kun at vælge 1,2,3 eller 4 tråds type.
  Eirik J (N):  Takk for svar. Tror ikke det er falskluft....har virkelig lett nøye. Men det med lambdasonde fra Biltema var et bra tips. 398,- i Norge... Sonden på CX'en er av type med 3 ledninger. 2 til forvarming og 1 til signal. Skal kjøpe en slik sonde og prøve. Lambdasonden er jo en "slitedel" uansett. Men må prøve å få målt CO'en før katalysatoren. Lurer på hvordan avgassene egentlig er. Noen som vet hvordan det kontrollstikket for CO fungerer?
   Kan legge til, at slik bilen er nå, så blir luggingen/rykningene 99% borte hvis jeg skrur co-skruen helt inn. Den går da fint på alle typer kjøring, men stopper på tomgang.
  Anders (DK): Jeg ville meget gerne at du igen og igen - kontrollerede indsugnings slangerne. Det er et meget velkendt problem på CX serie II GTI motorerne.
  Dagmatti: Jeg skal ikke være skråsikker utifra symptomene du beskriver, men prøver meg på et resonement som er relativt vanlig med L-jetronic innsprøynings-systemet, og vanlig på mange biler fra 80-tallet. Problemet er i såfall luftmengdemåleren. Motoren suger ikke luft jevnt (selv om turtallet er jevnt), særlig ikke på moderate turtall og ved lite gass (gass-spjeldet nesten lukket). L-jetronic har en utrolig dårlig luftmengdemåler, et spjeld/flapp som påvirkes av luftstrømmen inn i motoren. Flappen må være lett å bevege for å ikke gi treghet når du gir gass. Men når det er lett å bevege vil dette si at det også beveger seg i takt med den ujevne luftstrømmen motoren suger på moderate turtall med lite gass. Hvis flappen blir stående i en slags resonans med motorens ujevne sug, vil dette gi samme utslag som å trykke gassen rytmisk 1-2cm inn og ut. Man må altså prøve å finne en balanse mellom lite treghet og lite umotivert bevegelse. Strammheten i flappens oppheng har alt å si, og det som skal dempe de ufrivillige bevegelsene er hovedsaklig demperommet bak flappen. Det skal være betydelig treghet i dette rommet slik at raske bevegelser ikke får lov til å forplante seg til flappen. Vet ikke om tettheten på dette rommet kan justeres på cx'ene? Ellers vil jo alle fjærer som kobler til flappen dempe bevegelsene, og disse blir jo selvsagt slitt.

Stannar och har svårt för att starta:   Kalle 2002-03-08:
Bilen dör när jag kör. Startproblem efteråt. Tar lös tändläges givaren på svänghjulet, rengör den. Ruckar på kablarna på tändspolarna och tändstiften. Då brukar den hoppa igång, men det blir svårare och svårare varje gång att få igång den.   Anders (DK): Har du prøvet at kolla på vatten i benzinen? Plukke af fødeslangen et eller andet sted og før den til en klar burk, og prøvstarte motoren et par ganger. Tag af stikket til tændingen mod eldsfare! Vattenet er tydeligt at se som en gople flydende rundt i bunden af benzinen.

Hackande gång:   Hans W 2002-02-25:
Min CX 2.5 börjar rycka och gå illa efter någon km körning. Detta pågår ca 15-20 sekunder. Därefter går den hur bra som helst. Det har ingen betydelse om den har stått på m-värme eller kallstartats. Tycker att symptomen liknar brist i bränsletillförseln varför jag har bytt bränslefilter och besinslangarna. Problemet kvarstår dock. Mycket tacksam för tips. Den lokala cittraverkstan hade bara bränslefiltret att föreslå.   Örjan: Kolla tändkablarna samt anslutningskontakterna till tändspolarna. Andra alternativ kan vara vacumslangar, samt det grova veckade röret till insuget; måste vara helt till hundra procent.
  Mike: Kolla slangen till insuget, har aldrig sett en hel än, såvida det inte varit nytt. Mycket vanligt att det spricker. Kan ibland vara svårt att upptäcka, eftersom det gärna spricker på undersidan i vecken.
  Red. anm: Reservdelsnummer C-95596787
Luftflödesmätaren Insugsslang Slangen lossnat!   Michael S 2006-03-07:
Perhaps you remember about my CX stumbling and sputtering when the gas is applied? It would run ok as long as i didn't get on it too hard. Well, i discovered today that the big hose going into the intake manifold was barely hanging on, because the hose clamp was too loose. As the motor was running, i took the hose off by hand, and of course the motor died. Being a clever chap, I remounted the hose and tightened the clamp sufficiently, and voila! No more hesitating at all. Runs like a champ!

Ryckig gång:   Torstes 2000-06-29:
Min T1 85 modell har begynt å rykke/ha ujevn gange, dette spesielt ved turtall mellom 1500 - 3000 omdreininger/m. Det er jo stort sett innenfor det området du holder når du kjører normalt, så det er ekstra irriterende. Bilen begynte med dette etter å ha vært på verksted, så det kan jo godt hende at de har rotet til et eller annet. Noen som har peiling??   Herman: Hadde rykkig gange på min gti ved 2-3000 omdr. Feilen var en vakumslange som hadde røket. Slangen gikk fra noe sted på luftinsuget til insprøytingen. Hørte kraftig susing når jeg kjørte. Byttet slangen og nå er alt ok.

Ryckig gång:   Heinz 2002-01-29:
Jag har en CX GTI -88 som var omöjlig att köra på ettan och tvåan då den kom i självsvängning. Motorn svängde mellan fullgas och tomgång. Förutom på eventuelle fel i luftmängdmätaren mm så är en starkt bidragande orsak till fenomenet att Citroen begått ett allvarligt fel vid konstruktionen av luftintagssystemet. På låga växlar tenderar motorn att svänga bakåt vid gaspådrag beroende på elasticiteten i motorupphängningen. Därvid komprimeras den plastbälg, som sitter halvvägs mellan luftmängdmätaren och manifolden. Detta uppfattas av luftmängdmätaren som att luftflödet har upphört (att gaspedalen har släppts) och den stänger av bränsleflödet. När motorn då tappar dragkraften, svänger den framåt, bälgen sträcks och luftmängdmätaren tror att man ger gas. Resultatet blir självsvängning. En enkel åtgärd, som tar bort 80% av eländet, är att lossa rördelen med bälgen och vända den 180 grader så att bälgen kommer närmast intagsmanifolden. En klenare grenslang tenderar att få ett veck men detta kan åtgärdas genom att man lägger in en spiralfjäder som stöd. Nu blir volymförändringarna i bälgen betydligt mindre när motorn svänger fram och tillbaka. Verktyg: skruvmejsel. Arbetsinsats: ca 10 minuter! Är det f.ö. någon som vet hur man öppnar luftmängdmätaren på denna modell? Tidigare var locket skruvat men den här verkar helplastad.   Johan G: Aha! Detta var högintressant information. Ska genast prova och återkomma med resultat. LM är limmad med något epoxyliknande lim, men bara i kanten på locket; det går att få loss helt men var försiktig. Alternativt, skrota bort plastlocket och klura ut ett helt nytt. (Kom ihåg att inte mäta LM's rörelse med en ohm-meter. Du måste lägga en spänning (12V) och mäta potentialen för att få ett relevant mätvärde.)

Hackar:   Stefan 2002-01-28:
Min CX turbo -89 går inte rent, ibland! I motorvägsfart kan den gå jämt länge för att plötsligt börja hacka, går sen bra igen. tycker inte om att efter motorvägsfart i 3-4 tim. börja gå 50 - 70km/h. Kan gå hackigt vid kallstart men om jag accelererar upp går den jämt i accelerationen! Går lite bättre varm än kall.   Svar från Tore T: Den vanligaste orsaken till "orolig" gång är nog att motorn drar tjuvluft någonstans. På T2:an finns det mycket slang ock många kopplingar i "insugeriet" som kan läcka. Kolla ALLA dessa, minsta spricka och/eller otäthet måste åtgärdas. Det har skrivits mycket om det här tidigare på Citroënakuten...

Hackade till och dog:   Mike 2000-11-28:
Min 2400 Gti-84 hackade lite, fortsatte, hackade igen och dog. Den går på tomgång och om man varvar motorn men om jag lägger i en växel och försöker köra så hackar den och vill dö. Går då att varva upp med baktändning som föjld. Till slut gick det att smyga hem bilen (roligare bilturer har man varit ute på). Är det någon som har någon idé om vad jag skall börja med?   Alfred: Sjekk om du har lekkasje i innsugningsluften etter luftinntakskassen. Min oppførte seg på dette viset, og da hadde slangen løsnet fra målehuset for innsugningsluften, (foran høyre forhjul).

Kraftlös och ryckig gång:   Lennart 2000-11-15:
Min CX -84 blir plötsligt kraftlös; den svarar inte på gaspedalen, endast så att jag kan hålla den igång. Svart illaluktande rök kommer från avgasröret. Om jag vid dessa tillfällen stänger av motorn, får jag inte igång den. Motorn går inte ens runt. Den surrar bara lite svagt. Dessutom har den en ryckig gång innan den blir så där kraftlös.   Mike: Kolla insprutningsreläet. Jag hade liknande problem (30 km/h vid fullgas).
  Bosse: En annan variant, på insprutningsmotorerna, är om bälgen till insuget hoppar lös eller går sönder. Bilen blir kraftlös och förlorar ofta tomgången.
  Mike igen: Jag undrar om Lennart hittade felet på sin -84? Min -84 uppför sig på samma sätt och det är inte insprutningsreläet denna gången. det ser ut som alla slangar är hela och jag har börjat kolla alla kontakter. Är det någon som har ett eller flera tips?? Kablar och stift var det jag kollade först och gjorde rent. Stiften blir alldeles sotiga och om jag får igång bilen så låter den som en gammal traktor och ryker som en Ford. Det verkar som om den för för fet blandning (kanske). Är det vanligt att luftmängdsmätaren konstrar? eller skall jag leta efter ett kontaktfel? Just nu känns det som om jag skulle strunta i att byta balkar och dörr och i stället byta bil.

Ojämn motorgång:   Zoltan 2000-04-05:
I have a 2.5 GTi '88. My problem is: under 2000rpm in every gear when the car doesn't accelerate (I mean I don't push it, just hold it at a low speed) the engine jerks (ignition problem like feeling). If I push it pulls as hell, no jerking. Good compression values was measured (around 11 bars), sparks were changed, air-filter was changed, no air leaking was experienced. The engine seems to be in a good condition.   Alan D (UK): Suggestions (it is assumed that the 'ordinary' things like spark plugs and plug leads are OK?):-
A: the concertina tube at the left end of the inlet plenum - cracks at the bottom of the corrugations. It might not have been found because the engine moves to open the cracks when pulling.
B: the two interference suppressors on the coils. Get an electronic chap to test them. They are 2.2 mFd capacitors, and should still be OK at 100C.
C: if the CO adjusting screw on the air-meter (the box on the right wheel-arch between the filter and the throttle butterfly) is very much out of alignment it might affect the mixture at low throttle, but it would have to be missing completely to make the engine behave really badly.
D: worn track on the air-meter. This is bad news and can usually only be fixed by replacement.
E: has anyone been fiddling with the air-meter? If the seal of the black plastic cover is not done neatly, it may be that someone has been inside it and 'adjusted' it. NAUGHTY. I have a procedure to correct it. Contact me off-list to get a copy.
F: when the engine moves under power it flexes the cables at the back of the engine. Try to move them around while the engine is idling to see if they make any change. Do this first, because it is easy.
  Chris S: Check the hose that runs from the intake manifold to the air flow meter. Check it for cracks or rips. Mine got ripped and caused a horrible idle. Check all the hoses in that area, if any of them leak, it will cause the idle to suffer.

Jukser ved varm motor:   Børre H (No) 2001-11-29:
-84 CX 25 TRI (GTI). Når jeg stopper etter å ha kjørt motoren varm, og lar den stå en liten stund, kan den være idiot når jeg starter og begynner å kjøre. Hoster og harker, ryker svart, men går fint på tomgang. Inbiller meg at motortempmåleren øker og avtar veldig raskt. Har nettop skiftet termostat uten at det ble bedre. Noen som har prøvd å skifte temperaturføleren til innsprøytningen? Hva skal verdiene på denne være?   Thor Øivind J: Jeg har hatt 2 årsaker til noe slikt:
* Ventilen for tilleggsluft bak på motorblokken er slitt eller sitter fast
* Føleren for motortemperatur som styrer denne er ødelagt
Begge er enkle å skifte, men før du skifter noe: sjekk alle mulige luftlekkasjer og kontakter!
  Resultat från Børre: Jeg har byttet ut temp. føleren med en 300 ohms motstand, og nå funker det perfekt. Skal bytte når det passer seg sånn, men det funker helt greit ved minus 10 grader.
  Tillägg från Børre (januari): Har i lengre tid hatt svartrøyk og hakking med nesten død motor. Har prøvd det meste, men hva som skulle til var en rengjøring. Ingen kontakt i motorrommet til en CX er beregnet å stå ute. Løsning: motorvask, alle kontakter blåst ren med trykkluft og smurt med elektrofett. Deretter skikkelig behandling med motorplast slik at alt er isolert. Synderen var tilførselsplugg på starteren. Denne returforsyner strøm til tenningsanlegg slik at ved dårlig kontakt får coilene for liten spenning. Dermed ok tomgang, men ikke turtall på motoren. Har kjørt to dager i søle og regn samt spylt med vann dirkte i motorrom uten at min kjære har fusket en eneste gang. LYKKE!

Motorn rycker till:   Stefano 2001-04-27:
Min CX GTi-88 (ej turbo) har, (som så många andra) ryckningar vid cirka 1000-1500 rpm, sedan försvinner de. Har hitills bytt lambdasond och tändlägesgivare. Dessutom tagit loss luftflödesmätaren och försäkrat mig om att spjället går lätt och ledigt. Plus nya stift - NGK BPR6HS. Ryckningarna kvarstår om än i något mindre omfattning, så vad blir nästa steg? Vad är det man ändrar på, inuti luftflödesmätaren? Är det själva fjädern, eller det som är ovanpå fjädern? Kan det vara något annat, spolar etc.?   Tore T: Har haft samma problem på min T2 -89, men efter nedanstående åtgärd försvann bekymren: Ta först bort plastlocket på luftflödesmätaren, vilket man gör mycket försiktigt genom att peta in en skruvmejsel under den "tunna" kanten (locket är kilformat) och bända långsamt. Locket är klistrat, men när det gett med sig lite grand kan man dra loss det med händerna. Väl inne i luftflödesmätaren ser man den släpkontakt som går fram och tillbaka i en båge på ett "kretskort". Släpkontakten är dubbel och bildar något som ser ut som ett litet "skidspår" i det grafitfett som används som smörjmedel här. Det verkar som om släpkontakten "nöter upp" spåret för mycket kring det läge den oftast har vid normal belastning (man kan se det här med ett starkt förstoringsglas), med dålig kontakt som följd. Uteblir mätvärdet från luftflödesmätaren slår insprutningsdatorn ifrån. När sedan motorn rycker ändras luftpelaren i mätaren och spjället/släpkontakten flyttar till ett läge där det är kontakt igen och insprutningsdatorn får ett juste värde igen. Om man mycket försiktigt med sitt lillfinger (inga bomullstopz, det blir ludd kvar...!!!) smetar ut grafitfettet så att skidspåret försvinner, så försvinner också förhoppningsvis rycken kring 1000 - 2000 varv.

Defect air hose:   Mike B 2001-11-13:
Inspect the air hose from the metering box to the inlet manifold very carefully, if it is split or leaks when under pressure from the turbo the mixture will be very rich and you will get black smoke. Look especially under the bend near the manifold where you can't see easily I had a split which closed when the engine was idling so you must squeeze and manipulate it firmly to discover any holes.

Full stopp og bensin ut av eksosen:   Børre H /(NO) 2002-01-29:
Jadda, når alt var bare herlighet og glede så gav CX'n min opp igjen. 2,5 Injection 1984 modell. Gnist på plugger og bensin så det fosser ut av eksosrøret, men ikke antydning til start. Er 18 grader kaldt, og den bare stoppet plutselig, uten forvarsel. Tyder vel på el-feil. Skal det være spenning på to av de tre ledningene inn på coilene når tenning er på? Og står det konstant spenning på injectorene? Jerker: Råkade ut för exakt din beskrivning för nån månad sedan. Letade och letade fel men fann inget. Förrän jag hittade en lös luftslang. Satte tillbaka den, och sen dess har den gått som en klocka. Kanske har du samma problem. Men man antar ju alltid det värsta när gnista finns, bensinen flödar etc. Det var den stora grova från luftintaget/burken till insugsröret. Den hade helt enkelt lossat från luftburken. Men jag tror att minsta lilla läcka kan orsaka problem.
tillägg från Børre: Når den får stå lenge så hoster den litt, men dør. Motoren er full av bensin, og innsuget fullt av olje. Gnist, bensin og alle slanger er ok. Men ikke f.. om den vil gå. Bensinslanger og returslanger er åpne, og det er ikke kondens i systemet. Noen ideer, eller er det bare å skru ut motoren? Svar från Anders (DK): Troligen har du et problem med insprutnings ventiler, eller trykregulator ventilen samme sted. Kolla på hele det mekaniske rundt indsprutning ventiler og dyl. Olien du ser i indsugningen kommer fra vevhusets ventilationsslanger. Det kan reduceres ved at mindske diametern lidt inom den ene slange.

Misständning:   Anonym 2000-05-26:
I had a very weird misfire/hunting which lasted for ages and I couldn't find what it was. I had a new flywheel sensor fitted, new ignition leads, new coils and the injection system tested. This found nothing wrong. I then isolated the cylinder causing the problem by pulling the HT leads off one by one until I found the one that didn't make the engine die (it was number 2). It turned out to be a bad connection to the injector on that cylinder. Fixed in two minutes at no cost after about a month and £300 spent.

Rengöring av luftintagssystem:   Michael B 2001-08-20:
A couple of weeks ago I posted the problem with my 1988 CX25 Prestige (non turbo). It would stall when put into Drive. Suggestions included air hose leaks and an electrical problem resulting from engine movement. The car was towed to my mechanic and it came back on friday running absolutely perfectly. What he did was disassemble all the intake system and clean it out. These cars have a re-breather system and with the lack of highway speed driving here in Barbados the pipes all get clogged up. So it was all cleaned and is running beautifully. Also a clicking noise down below the oil filler cap turned out to be a faulty exhaust gasket and not the cam chain. So noise gone. But he has suggested that I replace the spark wires and the coils to ensure proper firing so I now have to locate parts.

Auxiliry air-valve:   Krisztian K 2000-09-27:
Some friend of mine told me that there is a capsule (located behind the engine) in the air input system of the engine, and this capsule sets additional air to be processed based on the temp of the engine - the capsule closes when the engine is warm. And there is a little screw on it, which can be moved up or down after loosening a bit, to adjust the amount. Is this really what that capsule does at the back of the engine?   Svar från Gábor: It's called the auxiliary air valve and it operates along these lines, yes. It is actually open when the engine starts from cold and will gradually close as it warms up (and it is also heated electrically, so it will close in due time no matter what). Its purpose is practically the same as that of an automatic choke on a carburetted engine: the extra air, which is also measured by the airflow meter, makes the ECU inject more fuel, to result in a richer mixture during warm-up. Adjusting only changes the opening position from which it will close anyway. Not all injection systems use this valve, some have a cold injector valve which simply injects additional fuel as dictated by the ECU, and contemporary systems use their idle control mechanism (valve or stepper motor) to achieve the same goal.
The manual says it is fully open at 20 degC, completely closed at normal engine temperature and if you feed it directly with 12 V, without the engine running (heated only by its own internal heater), it must close within 5 minutes. The warming up actually has two mechanisms in parallel: the mixture is made richer by both this valve and the injection (not the cold-start injector, but the normal ones). When started, the ECU adds about 50% more fuel than normal, and this surplus drops to around 25% in 30 seconds, then the coolant temperature sensor takes over and the surplus is reduced proportionally as the engine warms up. The auxiliary valve is an additional device the ECU knows nothing about, it only influences the electronics by inducing the airflow meter to send a higher signal because of the additional air.

Startproblem: Till toppen av sidan
Startar inte - jordfel:   Blair A (CAN) 2002-10-13:
  In the past week my 1988 CX 25 Prestige Automatic has been a wee bit stubborn to stay running at idle. When the gears are engaged - the engine stalls. This doesn't appear to be engine or coolant temperature related because it can be up to right temp and an hour later stop at a stop light. Always starts afterwards and runs reasonably until it happens again, say, 15 minutes later. The coils are new, the HT leads are new, the spark plugs are new, all in August.
   Now this morning, dashed to the garage, inserted the key, lovely fast starter sound - no brroooom! Turns over wonderfully but doesn't start! When I got home around noon I tried it again, same result.
   I can't recall if I've ever noticed a whining of the fuel pump, located aft and below the right rear passenger door. I left the ignition switch "on" and went around and listened carefully - nothing. Should there be? I remember that there was some discussion about a fuse or a relay that might be the cause. Would Big Blue, the relay-behind-the-right-side-headlamp, be at fault?


Big Blue - inprutningsreläet
  CGat: Basically one of two relays give problems in that area; Big Blue and the injector relay. Due to the location of these relays they can suffer corrosion (if you replace these relays, cover them with a polythene bag and seal it to keep the moisture out).
   Check if there is power up to Big Blue, run a meter to the large gauge cables on the plug and to a suitable ground point should be 12 volt. A quick test to operate the pump is to short out the two large gauge blue wires found on Big Blue's mutliplug - the pump should then be heard running.
  No pump sound? Run a positive pole cable from the pump to the battery, this should prove the pump condition is ok.
  Pump doesn't run? Bad ground connection or bad pump! Put a meter (multimeter) across the pump terminals (still connected upto the cars wiring) and turn the ignition key. No voltage....theres a break in the supply from Big Blue to the pump. To prove this run a secondary cable from Big Blue to the pump and repeat test and all should be well.
  Paul: On my Lancia (which also has Bosch L-Jetronic) if you push open the flap in the air flow meter all the way it will cause the fuel pump to run when the ignition is on. Might be another test to do.
  Shane L: There is only two times my CX has let us down. First time it was big blue .... or so we thought. The fuel pump wasn't running so it was a simple matter of hot wiring the pump to get home. My father cleaned all the terminals on big blue, decided the relay must've been dead so paid a (large) amount of $ for a new relay. In the mean time I've grabbed the old relay, dissassembled it and cleaned it's dirty contacts. As far as I could see it should work. The new 'big blue' relay didn't solve the problem, so it was returned and the $ refund. My father mucked around for days scratching his head, wondering why the mongrel wouldn't run.... Then testing the voltage yet again at big blue, this time he jamned the multi meter prong up into the bottom of the connector of the small wire on big blue. The relay clicked..... Yeah, the whole time it'd been a dirty connection on the small wire on the plug of big blue even though it'd been cleaned several times.
  Chris S: This sounds very much like a simple hot idle mixture problem. There is a screw on the air meter box for adjusting the meter bypass air at idle, however it would be best to have this done by an EFI shop so they can make sure the result meets any legal emission regulations you may have. But if you must, try twiddling it in & out a bit, however something else in the engine must have changed to cause this adjustment need - how long ago were your injectors serviced?.
  Wendham: Try the electrical connection under the carpet in the front footwell (under the driver's feet in RHD cars, so presumably under the passenger's in yours). It connets Big Blue with fuel pump.
  Blair A: In answer to your question, I have never had the injectors serviced since I've had the car - three years. Even if I use the highest octane and grade of petrol and put in a can of injector cleaner every 4th fill-up, what "service" do the injectors require?   Chris S: They "experts" say it needs to be done once in a while, I guess about every 2 years or so. They dissemble the injectors & put them in an ultrasonic bath, inspect, repair/replace the needles and/or seats, fit new O rings, replace the short injector/rail hoses, set the idle mix and charge you $A 400!! Have had it done twice on my car, think its coming up for another one very soon.
  Surprised you use "Injector Cleaner" fuel additive on your car, a cat convertor car if I recall. Here its a no no, on cat convertor cars, the cleaner has stuff in it which poisons the convertor & is known to give injector problems. Maybe you have different cleaners from ours, but the injector people say don't believe the label & despite them saying this cos it might cut them out. Don't want to scare you, but my mate successfully poisoned his BX's cat with fuel added "injector cleaner", dirtied his injectors and fouled the plugs the spark plugs turning them a kinda rusty colour inside. He got everything sorted out: new cat (non genuine - 1/10 price of Cit), injector service & new plugs.
  Gary M: I have never had the injectors serviced in 8 years. I don't think with clean running engines and fuel it would be required very often. I hate to say sometimes too much additive might cause a problem but most of the time no. Are you sure this isn't the old "leaky concertina rubber intake tube" that leaks when the engine moves a little on acceleration? Or leaky intake manifold itself?
  Blair A: Gentle ListFolk: I have been in the garage for a couple of hours and here's what I can report:
1) I checked the "concertina rubber intake tube". It appears to be intact. Upon flexing (with it removed from the car) there are no noticeable breaks. When I insert a torch (flashlight) with an open bulb and move the concertina around, there is no light escaping. I am prepared to say that it is NOT the concertina.
2) All vacuum lines are intact and don't leak.
3) All fuel lines appear to be intact and no leaks apparent.
4) I managed to get "Big Blue" dislodged. It had a clever little sleeve covering it which disguised it very well. I don't know how many other owners have this, but it appears to be "stock". It has an elastic cuff at the top which encloses the relay very effectively - about 13 cm in length, it tapers at the opposite end where the wires exit. When I switched on the ignition and removed the relay from the multiplug connector, there was no click from the relay itself - no click when re-connected.
5) I found a good ground point and tested each of the sockets in the multiplug. Here are the results:
15 - 11.730 V DC
30 - 11.87 V DC
31 - 00.009 V DC
50 - 00.000 V DC
87 - 00.000 V DC
87b- 00.030 V DC
TD - 00.030 V DC
There are no differences in readings between the sockets (relay side) and the wire entrance (connector) side.
6) I shorted out the two large blue wires in the multiplug and there was no discernable sound from the fuel pump although there was a small, hardly visible, consistent spark when sockets initially touched.
7) I checked and determined conductivity with all fuses in the fuse-box.
Does this information provide any further ideas as to how to proceed? Thanks to everyone. What would I do without you? By the way, the nearest CX is probably 1300 kms away! CHEERS! Blair...
  Alan D: 1) Disconnect the spade connector above the battery which provides power to the starter solenoid.
2) Twist the key to the 'start' position. This goes through the motions of starting but prevents the racket from the starter motor drowning our other sounds.
a) Is there a buzz from the pump?
b) If not, is there a click from 'Big Blue'?
From these observations you can diagnose where you should be looking.
  Sheddan: Can you reach under and give the fuel pump a tap with some thing metalic. I had one that failed and would go for 1000s of km then falter, when it did , put onto high quick and get out and tap fuel pump. it would then burst back into life.
  Harry S: Along with the fuel relay and the flywheel sensors I would look carefully for a vacuum leak. It will lean out the mixture. As the engine is engaged it rocks and will sometimes open a crack in a line. There are a lot of hoses to the manifold, the accordion pipe, the AC idle control and the basic idle control. Any one will cause this sort of trouble. If it won't start at all the hose may have broken completely.
  Wilfred: The stalling when engaging the gears is a typical behaviour when the cortina is damaged. Although you checked it, check all hosing of the air intake. I had (have, temporarily fixed with ducttape) a crack that is large but hardly visible, it shows only when disassembling and gave me a lot of trouble. Not starting at all and sponteaneous stalling I've had to, which was fixed after cleaning one of the connectors on the ignition computer (just above the battery). About the big-blue, it is supposed to drive both the ignition and the fuel pump, that's why there is a 87 en 87b connection, they both become active when: 1) the starter is engaged 2) the engine is running. It is a kind of protection but for testing and emergency it's no problem feeding connecting both with the switched power lead (I think 50 but I'm not sure).
  Ted P: Blair, I might not be so confident in excluding a leaky manifold based on a visual inspection. A more certain examination is to plug the air intake at its opening between the headlight and radiator (styrofoam cup)and attach an air pump at one of the vacuum connections. A pump with a pressure guage is best, as you can quantify the rate of pressure increase and decrease over time. Check that all electrical connections have their rubber boots properly in place ( air meter on top of the filter & throttle switches). Put the entire manifold under pressure & spray it with a mist of soapy water/ Windex. (engine off, of course.) A household mister bottle works perfectly. If there is a leak, you'll see bubbles. The usual suspects are the connections between the accordian and the neighboring ductwork. Duct tape is an excellent fix, and much cheaper than a new accordian. THEN, re-attach the vacuum connection where you placed the air pump nozzle, and re-test the system from another point. You want to make sure that that the vacuum system you disconnected for the first test is not a secondary source of leaks.
  NB that stupid reasonator that branches from the airbox behind the radiator often melts from the exhaust manifold heat. This is upstream of the air meter (and thus irrelevant to the issue of stalling) but it will prevent you from getting positive pressure on the system. WHY they put a resonator on the intake system but no cover for the bottom of the flywheel housing is beyond me. Don't forget to take out the styrofoam cup when you're done, or the car will never start. The nature of a failure is usually indicative of its origin. Problems caused by air leaks in the intake system tend to be gradual and intermittent, worsening over time. A leaky manifold makes the fuel/air mixture too lean. After a certain point, the engine starts to stumble, and the L-Jetronic system will enrich the mixture to stabilize the idle. Problems caused by electrical faults in the fuel system tend to be definite - there is electricity or there isn't.
  There is an excellent book on Bosch Injection Systems: "Bosch Fuel Injection and Engine Management" by Charles O. Probst. It provides a clear introduction to L (electronic) and K (mechanical) injection systems. It starts with a theoretical discussion of the systems, advances to a explanation of the systems' function in automotive applications, and then offers some troubleshooting and service tips. It's a must-read for those of us who have to explain to the mechanic how our cars work. It also provides a list of cars sold with the respective systems, which may provide guidance on selection of a service shop. (i.e. M-B and VW were almost exclusively K-jetronic, a totally different system than on the CX.) Here's the Amazon link for the book. Order it today, it's on your doorstep tomorrow morning.
  Blair A: Gentle ListFolk: Thanks again for all the suggestions and advice. It's deeply appreciated. Progress this morning:
   1) I removed all piping between the air flow meter and the air plenum, cleaned up everything and tested for leaks. I used an air pump with a gauge and sealed each pipe/tube and employed a spray of washing-up liquid mixed with water. There were no leaks on any of the pipes/tubing, so all were re-fitted.
   2) When I came to the accordian (concertina) tube, it was difficult to get the tube sealed, but when I did, a very small crack was apparent in one of the folds. This was cleaned carefully and sealed with rubber contact cement and covered with hot glue. It was left to "cure" for an hour and, after re-testing positively, was re-fitted to the car.
3)    3) While this was happening, I sealed the opening to the air plenum as well as all the vacuum outlets, &c. Applying a small amount of air to one of these vacuum ports, the gauge went up to 10 pounds per square inch and the regulator on the air pump kicked in. It stayed at exactly 10 lbs/sq. Inch for ten minutes. When I sprayed the washing-up/water solution over the air plenum, there were no bubbles. Therefore, I can now categorically state that the plenum is air-tight.
   4) I re-fitting all the tubes/connections and the concertina tube, sat in the car and turned the key with cautious optimism. Nothing!
   Can someone with experience direct me to the exact location of the fuel pump? I don't hear any buzzing/whirring at all with the solenoid connection removed and the key turned to the "ignition" setting, so I am, therefore, leaning towards the fuel pump - either an electrical connection or the pump itself.
  Marc B: To begin, you can short pins 30, 87b and 87 in big blue. As a result, the fuel pump should be hotwired, and the injection computer shoiuld be powered. If when starting now yiou don't get fuel smell in the exhaust after a while there is definitely trouble in the injection system. However, the symptoms look more like an air leak. When putting the box in gear, the engine moves a bit. This opens a crack, with annoying results on idle. There are a LOT of vacuum hoses, and none of them may leak. Essentially: After the air filter/resonator there is the air flow meter and from there a split: splits to A/C on bypass valve and hoses (back to injection manifold), idle regulating bypass hoses (routed back to injection manifold), cold running regulating bypass hose (routed back to injection manifold), and continues through crack-prone concertina. After that, crank case ventilation joins (a hose that disintegrates after a while from the effect of oil fumes, check where a hard part joins a soft part) and we find the throttle valve. After that another line branches off, for the inlet manifold vacuum sensor (for ignition vacuum advance). Another hose branches off to the fuel pressure regulator. Don't forget to disconnect the Big Blue after testing: it will power the fuel pump even with the ignition off and thus drain the battery, and also: a fully pressurized and unattended fuel system is a fire hazard.
  Paul: The approximately 5/8" ID hose that goes from the bit where the idle screw is to the accordian thing totally and cleanly broken in half yesterday on the way home form work on my car (CX fuel injected). The car still would start and run it just would not idle. Bottom line is that I don't think a small air leak would keep Blair's car from starting. I still think it's the fuel pump.
  Alan D: The fuel pump is infront of the right rear wheel. Check the connection below the right front carpet FIRST. It is a single spade connector in a cable running from front to rear.
  Harry S: If your fuel pump does not work and the relay does, the connection under the passenger floor carpet (power to fuel pump from relay) is bad or your fuel pump is bad. I would lift the carpet and solder the wire connection there together. Mine looked fine and intermittently caused a no-start condition. I would also check the two multi-strand plugs to the injector computer (over the battery). Wiggling them has started the car at times.
  Shane L: Have you checked the wire running under the front carpet to the fuel pump yet??? I'm sure someone has already mentioned this. I think the BX has the same stupid design. Wiggle your feet around on the carpet and see if the car suddenly runs... Hang on you LHD, get your passenger to jump around :-) I heard of someone with a BX, it'd stop on his wife all the time and refuse to run. He'd turn up, step into the car, move the seat so he could fit in and the car would start instantly.... This went of for sometime. Eventualy they traced the problem to this same wire. He'd get into the car, step on the fuel pump wire as he moved the seat and the car would start .................
   Marek: First, I bet it´s a fuel pump. How you can check it ?. Try to start the engine for a while, then check the spark plugs. Are the wet ? If no, there is promlem with fuel delivery. You cen reach the fuel pump with your hand even if the car is in lower position. Let someone to start it. Do you feel the pump is running ? Or is it just a short click then nothing. If the pump is running, the problem cud be in EFI management. If it´s just clik, check the fuel filter first. If ther will be fuel pressure between the pump and filter = > go for a new filter. (On turbo models, it´s right behind the pump, on other it´s in engine bay near dogbone engine mount). If no fuel presure is present, it is siezed fuel pump. I´m sure the leads to pump is OK, beacouse you wrote about spark when shorted the connectors. But you can easily check it on pump´s connectors with meter or bulb. It must go on when starting and stay on for a short time. If the fuel pump is bad, you can use one from any CX or another one, which is giving 2,5 bar presure.One from BX multipoint will work great (tested). Enjoy CX owning!
  Blair A: Gentle ListFolk: Spent the last four hours this morning (-4°C) in the garage and here's what I've done:
   Big Blue - contacts are all fine - clean, like new. Big Blue is sealed so don't think it could be corrosion. Should I attempt to get the (sealed) case off and check the workings inside? Multimeter readings at multiplug in previous posting (when ignition "on".) As I'm alone, I cannot engage the starter and tap the relay at the same time. No cracks or loose vacuum lines. All are connected well and where they should be. Disconnected and reconnected the flywheel sensor connector. Cleaned both sides. Appears to be "good". I have a spare sensor. Should I replace? Remember, the temperature is nowhere near "hot". Do they just fail?
   Can't tell if the fuel pump is running. I have given it a few solid taps with a small hammer. No difference to starting. Which is the solenoid connector near the battery? If I disconnect this, I should be able to turn the key and hear the fuel pump because the starter will not engage, right? ;-) I have requested a quote from Andre Pol for a new pump. I'll have to figure out how to get the rear of the car up high enough (and safe enough) to crawl under to check the electrical connections and, if necessary, replace the unit. Has anyone on the list replaced a fuel pump in recent memory? The car only has 75,000 miles on the odometer. (121,000 kms) I can see the pump - where is the fuel filter located? (I haven't had the courage to crawl completely under the car and won't until I can be secure.)
   Electrical connector under the carpet in the front footwell has been renewed and taped.
   Removed spark plug for #1 cylinder - electrode is light brown - no indication of excess (raw) fuel present nor rich or lean running prior to failure to start. Can coils fail suddenly? Remember, they were new just prior to the ICCCR trip. Never a moment's trouble at all during the trip. Fuel consumption was above-average.
  Based on tests performed yesterday, the intake manifold (plenum) is air-tight and not leaking.
   I checked and cleaned the connections in the two multiplugs to the injection computer on the left wheel well.
  Scott R: Blair, you have not done the easy test: see if there is voltage AT THE PUMP ITSELF, and listen there to see if it is running. No pump, no go. If no voltage, find why; if volts but no pump, new pump time. You might also be able to loosen a fuel fitting on the injector feed and see if fule squirts out, but don't set anything on fire. Since you ahve tested most of the rest and not confirmed the state of this, I strongly believe that this is the path to follow now...before it gets to be -20 deg C in the garage!
  Paul R: Blair, you don't have a floor jack? Get one and you can use the rear subframe to raise the rear and get a stand under the jacking point. Take a couple of long leads and jump them to the pump directly, see if it runs then.
   The starter solenoid wire is easy to find. It is encased alongside the positive battery lead going to the starter. Find where the small wire comes out of the 'tube' holding the positive lead and trace it toward the driver's side fender, you'll find a spade connector there. Just disconnect that and you can turn the key on to find out if the pump works.
   While Big Blue seems sealed it can still get corroded inside, although yours probably isn't due to the factory cover.
   I'm not sure but the fuel filter is just after the pump, isn't it? You should find it and make sure it isn't clogged (you should be able to blow through it).
   Chin up, things can only get better because the next thing to happen is the car will run again! In other words, you can only go up from here! But this should be a warning to everyone, don't allow 'small' running problems with IE engines persist because they will eventually become big disabling problems.
  Adrian: There's an easy way to check if your fuel pump is working. Just see if you have fuel pressure. The supply hose goes into the fuel filtre on the right of the engine bay and is easily accessible. You can loosen the output hose clamp and see if raw fuel squirts out. If you want, release all the pressure, then reattach and try starting the car. Then check to see if the fuel pressure has been pumped up again. If so, of course the pump is working.
  Shane L: That fuel pump wire ..... under the front carpet....... did you ever check it??? The engine is obviously getting no petrol, the pump isn't running so forget the rest of the stuff your looking at and concentrate on this. When big blue played up on my car we simply hot wired the fuel pump. To prove it's just the fuel pump wire to yourself (and us ;-)). Grab a long bit of wire, run it from the battery to the fuel pump......... Does she now run when you try to start her??? If the fuel pump won't run like this, grab a jumper lead, clip it to an earth point and to the pump for the earth. Pllllleeeeeaasseeee letus know if this works ;-) Forget all the intake stuff under the bonnet until you get that fuel pump running !!
  Paul: SERIOUSLY Blair, if you take the accordian off of the air flow meter you'll see a little flap in there. If you open it all the way...you may have to take the meter off to push it from the other side...it moves really freely....the fuel pump should turn on if the key is in the run position. I think the Bosch engineers put that in for test purposes. Someone mentioned the Bosch book a few posts back. I think I read it in there.
  Marc B: To hear the fuel pump with the starter solenoid disconnected you still need to hold the key manually in the start position. Better is to use a wire with three spade connectors and short pins 30, 87 and 87a in the connector from big blue. Big blue removed of course. This will hotwire fuel pump and injection computer. So having done this, walk to the back of the car and listen for fuel pump buzz. No buzz? Check for 12 V at the connector under the carpet. No 12 V? Check for broken wire between big blue and under carpet. Voltage? Check for 12 V at the pump. Still no voltage? replace wire. 12 V at pump but pump not running? Replace pump. Buzzing? So the pump was running all the time? Check for fuel pressure in injector line (replace one injector for piece of hose and gauge). Should be as specified. Fuel pressure in injector line but still no go when trying to start? Remove all four injectors from engine block and hang them in glass jars. Attach well. Start again. Fuel should be delivered. No fuel? Problem with injection computer wiring or with the signal from the ignition to injection. Make sure there is ignition at this point, the ignition computer triggers the injection. If there is ignition and all your air lines are OK it is most likely wiring of the injection system. If there is fuel, ignition and no leaks in the air system the injectors stay open too long or at the wrong time. Time for a new wiring loom (been there...) The fuel filter is located under the hood (bonnet) just before the injection rail. Clamped to the front crossframe in front of the verntialtion air intake tower.
(Can coils fail suddenly? Usually just one at a time. You would have noticed. Is temperature sensitive just like the flywheel sensor. Funny effect on the highway on the way to get a replacement for it: engine runs well, car goes fast in the direction of Citroen parts suplier... engine gets hotter. Coil breaks. Sudden loss of power. Car drives only 80 km/h and engine cools, as half of the injected fuel is never ignited. Coil cools as well and restores contact. Engine suddenly comes back to life... car speeds up. Ten minutes later the cycle repeats. Worst was the last km of city traffic to get at the place: hot engine so only two cylinders and needing to do stop and go traffic...)
  Blair A: Gentle ListFolk: I bridged #87, 87b, 30 in the "Big Blue" relay multi-plug on the advice of a few ListFolk with special "thanks" to Chris Stuart for sending a large, clear, explicit diagram of the connections and their purposes. As soon as #87b and 30 were bridged, the fuel pump sprang to life. Man - is it LOUD. I can't believe I've never heard it before. My engine is relatively quiet, but it always just blended in...
  Two plugs were removed and the bodies were lain on the rocker cover. The garage lamps were switched off and I engaged the ignition switch. There were sparks present at each of the plugs. I stopped after only a few seconds and ran around to the front and stuck my nose in the spark plug wells. Tell-tale odour of fine, fresh 92-octane Esso Super fuel vapours. Disconnected the relay bridge wiring. Needless to say, the car didn't start. Oil spot removed from bridge of nose...
   The fuel filter is not blocked, obviously, as there is fuel present. To double-check, I removed the connection from the filter as it enters the fuel rail and inserted the end into a glass jar. Bridged #87b and 30 again - nice flow of fuel. Disconnected bridge after a few seconds. I can't measure the rate, but it appears to be satisfactory. Re-connected the fuel line.
   Re-connected "Big Blue".
   Checked the temperature sensor at the right-hand end of the head. Cleaned connections in connector and on sensor, packed connector with "Vaseline" and re-connected.
   I did try starting the car with the plugs in and big blue 'bridged' so that the fuel pump was definately running. I did it immediately after bridging the connections in "Big Blue" - before I removed the plugs to check for spark and fuel.
   Last thing to do, I suppose, is replace the flywheel sensor.
   So, I have fuel and I have spark. Shouldn't this be sufficient - or do I need a plastic, head-bobbing miniature deity glued to by dashboard to appease whatever gods are smiling at this moment?
  Paul: Umm....well the last thing you need in the equation is compression. Have you checked that? Compression gauges are handy and rather cheap. I'm new to Citroens so excuse my ignorance but do these OHV engines have a timing belt or a chain? If it's a belt it could have skipped a tooth. I suppose a chain could have too but I just don't know that much about chains.
  Robert T: I've been reluctant to mention this because it doesn't quite match your symptoms and because it falls into the 'looking for the complex solution to a simple problem' category. But this did actually happen to my car (81 CX2400 Pallas with carburettor and conventional points ignition). The car stranded my wife in the hospital car park. And you guessed right - it was wet and windy winter evening. Engine would fire while cranking but died immediately when the key was released to the 'run' position. I hot wired the car to drive it home. The contacts in the ignition switch were too dirty to allow sufficient current for normal ignition (about 5 amps). I did manage to dismantle and clean the contactors which solved the problem. The contactor body has some small, loose bits and some springs. Dismantle it slowly and be careful not to loose any of the bits. I fitted a new switch soon after as the old one was pretty worn out mechanically. So, Blair, it might be worth checking that the ignition circuit is actually getting power in both the 'run' and 'start' positions and that the switch is capable of allowing sufficient current.
  John H: I should say "GROUNDS"....Yes I have been following Blair's tale. I had this problem earlier this year, every time I went near it with my tools at the ready it wolud damn well start. It proved to be the crank sensor. I now maintain that testing these for 70 ohms is a waste of time. I think that merely touching the Multitester probes to the terminals can "make" them "connect" again and they can read OK. But as soon as you remove the tester they return to their naughtiness. To prove my point, whilst waiting for delivery of my new sensor, whenever the car didn't start I would get under the bonnet and give the plug a wiggle and the car would then start.
  Scott R: The battery (unless of the sealed type, and even then I have my doubts) gives off corrosive vapor and mist. ANY CONNECTION near it should always be suspect. The above is an excellent example.
  Blair A 2002-10-18: Gentle (and patient) ListFolk: I just came back in from the garage. The smile on my face is reflected on my screen... The car starts and runs - beautifully! Before I tell everyone what the problem was, I need to elaborate...
   I was sitting and thinking and reached for a document that Bill S from New Zealand sent me - from Citroën Customer Services, After-sales Technical Department - Technical Bulletin No. 22 = CX 25 I.E. Vehicles - All Models - "Electrical Incident" - dated 19th April, 1988. It starts out: "For all electrical incidents on CX vehicles with fuel injection -> 88 Model Year, it is necessary before fault finding or changing units to carry out the following operations and modifications:
   A - On -> 88 M.Y. Vehicles:
- Check and improve the electrical contacts between harnesses and units.
- Check and improve the electrical contacts on connectors between harnesses.
- Check earth connections.
- Check the run of the harnesses and their attachment points.
   B - On -> 87 M.Y. Vehicles:
- Carry out the operations in Paragraph A.
- Improve the sealing of the electrical relays.
- Ensure the sealing of the L.H. Front wheel arch.
   Now, I read this and thought, "I've done everything except check the earth connections. So, I went out to the garage again and checked the diagram provided with the document with my car and disconnected the battery and disconnected, fixed new connectors, cleaned and made shiny everything I could that was "grounded" or "earthed". Still nothing... There was one grounding point still to go. It was located above the battery, below the black box on the L/H front of the wheel arch. I removed all the connections, cut them off, stripped the wires back, checking for corrosion and, if none was found, fixed new connectors. I removed the mounting bolt and, with a wire brush attachment on my bench grinder, cleaned it up so it shone. I re-attached the bolt and all the connections and tightened everything down. I turned the ignition switch - nothing. I then re-connected the battery. I turned the ignition switch - it started! Just like summer - two "yes - yes"'s from the starter and the engine was idling smoothly. Could that have been it? A ground? - A GROUND?
   So, the moral of this sad tale is: "CHECK YOUR GROUNDS!" Now - go right out to your car and check your grounds... We'll all wait here while you do. If you don't have access to a CX, find someone who does and ask them, "Have you checked your grounds?" In fact, I propose that, whenever two or more of us are together, the Secret CX Society passphrase will be, "Have you checked your grounds?" I will leave the secret society handshake and apparel to other fine ListFolk to decide.
   Thanks to all those who participated in helping with the process. It may be a week that I will never get back, but I feel oddly satisfied and content. I now know that every possible electrical connection, connector, wire, and cable-run in my engine compartment is intact and doing what it should. I know that "Big Blue" retains its peculiar status as an ardent and uncomplaining worker for the cause. I know that all the vacuum lines, fuel lines, fuel pump, fuel filter, concertinas, and hoses are intact (and incredibly clean!). This car never had it so good. (By the way, it's NOT for sale any more...) ;-)
   Now, one final request: I noticed that there was a marked amount of grime and dirt in the L/H wheel arch area of the engine compartment that I'd never noticed before. This was because the rubber ear or cover between the wheel arch and the engine compartment is missing. This must have come off when I went through an enormous lake of water at speed during a torrential rain storm. Since it is now lying at the side of the road somewhere between Sheboygan and Manitowac, Wisconsin, does anyone have one lying about with the funny (odd) plastic connectors to attach it? I need one. I will pay for it and the shipping and handling. (Don't handle it TOO much!) ;-) Contact me off-list if you can assist.
   Oh - and there's an "Open House" at my place this evening at 8:00 PM to celebrate "the week that was" - all are cordially invited. Drinks, snacks, entertainment, discussion, dancing - all free-of-charge. Gold Citroën Waterman fountain pen for the first arrival. Come early and stay late! R.S.V.P. off-list. ;-) CHEERS! Blair...
  Chris B: Blair, great to hear that your CX is running properly again :-) So your saga confirms the oft repeated advice given in the UK Citroen Car Club magazine that, whenever you buy a "new" Citroen, always take apart, clean & seal every electrical connection you can lay your hands on.......................!

Kortslutning i kabelhärvan till insprutningen: Marc B (NL) 2001-02-07:
  My -86 25 GTi suddenly died. Engine stopped and refused to restart. At best would make five seconds of very unhappy revving. It cut out driving on a straight country road doing 80 km/h purring nicely. I am puzzled by what is wrong, as together with the guy from roadservice found out: all four spark plugs give sparks, fuel is being injected (and after a while must have been possible to smell it 50 meters from the car). Anyone any hints on what is going on? The car is the two flywheel sensor AEI/EFI engine (electronic ignition, no distributor), Bosch L Jetronic fuel injection.   Rogier V: As you got sparks and fuel - what about air: way to much air (false air suction - running way too poor), no air at all (running way too rich). Maybe some inlet hose just got loose? What did the spark plugs look like; white, brown or black?
  Alan D: Engine block temperature sensor open circuit makes the injection push in a lot of fuel and floods the spark plugs. The sensor is at the right end of the block where a 'fifth injector' might be if there were one. Another possibility is broken wiring to the air-meter. This may make the injection computer work as if lots of air is going into the engine = lots of fuel.
  Marc B: Thanks for the suggestions. My garage informed me they measured resistance of the spark plug cables and found they were bad and replaced them. They measured the flywheel pickup sensors as well and found those OK. They checked compression as a head gasket failure seemed not unlogical to me at first, that wasn't it though. As far as air is concerned: the day before the sudden stop I replaced the cold start auxiliary air valve, thus I had to readjust idle speed. Doing so the car idled very smooth, even when cold, and when revving the engine no hissing sounds (air leaks) were heard. Thus I ruled out an air leak. Additionally, with an air leak problem mostly occur when idling, not when driving at considerable and constant speed. Maybe the car has a mind of its own and decided that within 1.5 week of having the exhaust flex pipe replaced it just wanted to see the inside of a garage again...   Gary D M: Many times with older cars, even well kept, the place to look when something goes wrong after something else has been fixed is around the place last worked on. What about the wire to the oxygen sensor, because of the work on the flex pipe (do you have an oxygen sensor?). (Also if the flex pipe is broken I have found on my car that it is probably because I have not replaced the motor mounts soon enough and the movement flexes the pipe too much.)
  Gábor: A smaller leak, yes, but with the suddenness you mentioned it could have been a complete hose popping off. If you have just changed something around the auxilary air valve, this is the very first thing I would check. It might not be that operational after all or the hoses disturbed might have come off, or something similar. Much more likely than the ignition cables dying in an instant.
  Marc B: Thanks for the suggestions on my still dead 25 GTi. I reported on the alledgedly bad spark plug cables, it turned out they were not the cause - the car still did not run. Next suspect was the ignition computer. This morning I went to pick up a replacement one at a CX specialist, fitting it didn't get the car to start. So that keeps me with a few suggestions: broken/damaged wiring to the air-meter - should check this one out, wiring in a CX is always suspect number 1. No oxygen sensor, no cat fitted to it. The auxiliary air valve itself should be OK, at least after installing and the next day as well it worked better than the faulty one I took off.   Gábor: Ignition cables: no wonder, no plug cable can cause such a quick failure. The ignition computer: hardly ever, they always start with this one among the prime suspects, but it should be the last one. They can go wrong but they don't do nearly as often as garages claim. Air-hoses: that would be the first to do (not always but sure in your case where you confirmed that you have both fuel and spark). Going through all hoses methodically including those going and coming from the auxiliary air valve. You could also try to disconnect the auxiliary air valve and plug both holes where the pipes were attached. The car should start without the auxiliary air valve, it might require some throttle to start and to keep running until warmed up but it should run just fine. If one of the two hoses going to the auxiliary air valve developed a large leak (for instance, the jubilee clip cutting into an older and already rigid hose), that would cause the very symptoms you described.
  I do insist on these air hoses, because if you have fuel and spark as you described, the problem could not be some misadjustment or smaller problem. The engine should start even if it runs erratically or stalls. I even doubt the problem of wiring between the AFS and the ECU -- that would make the car a non-runner, sure, but you wouldn't have fuel from the injectors then.
  Jeff: "No plug cable can cause such a quick failure" - Au contraire: my '87 Lincoln Town Car had just such a failure, it was a leaky coil wire, so much so that it looked like a small welding shop under the bonnet!
  Marc B 2001-02-19: This morning I plugged my own AEI computer in a running -86 GTi at Citroville and tried to start it. No problem! So until now I found out: my car is still dead after a sudden death. Mechanically it should be OK; compression test done, ignition computer works, new spark plugs, cables, coils should warrant working ignition if wiring and sensors OK. Measured all wiring to peripherals on computer multiplug, seems OK. However, sparks does not look strong enough. Failure may be: lug for second sensor has come off torque converter (hint from Citroville). Otherwise: shorting the big blue relay gives an audible sound from the fuel pump. While cranking the fuel pressure in the injection rail is 2.5 bar. None of the injectors are causing a short circuit. So fuel should be injected unless the signal from the ignition computer does not arrive at injection ECU. No leaks in air system. This rules out: connector for fuel pump under passenger carpet. Tomorrow the dealer will start working on it. Keeping my fingers crossed the bill won't exceed a months salary...   Gábor: Measure the injector signal with a preferably good quality multimeter (analog ones are usually much better in this respect). As you push on the throttle and the pulses become more frequent, the effective voltage measured should rise, so you can at least have a confirmation that the ECU does talk to the injectors somehow. If there is fuel smell, the ignition is still the prime suspect. Even if your coil, cable and plugs are all right, do they receive signal? According to the diagram I have just received, the ignition module has its own MAP-like (vacuum) sensor, it does not use the AFS of the injection (although they practically do the same). I don't know where exactly it is located (somewhere attached to the inlet manifold, I suppose) but it connects to pins 3, 4 and 10 of the AEI. But that's the second step, the first one would be to see whether the coils receive any good signal from pins 9 and 1. By the way, did you check the coil capacitors? A shorted capacitor there would upset the applecart. Also, although it might sound stupid, did you check the 12V on the upper end of the coils? And to the AEI? Both comes through the ignition switch and several single connectors, any of them might be giving trouble.
  Marc 2001-02-24: The engine runs now, but only when a hefty clamp is used around the fuel supply line; the injectors stay open all time (even with a new computer) and if not clamping the fuel supply the engine is choked to death (too much fuel). Took out the wiring loom to find the short, and from another car with the same setup took a new wiring loom (as replacement). Now want to do the same as with the AEI: measure all the pins on the injection computer for the right voltage/resistance. However: I do not have a matching diagram of the wiring (yes, I have a Haynes). The file that is available at http://groups.yahoo.com/group/CX-L/files/efi.gif does not seem to be correct: it gives connections to the EFI computer multiplug at pins (a) while in my car (and in the loomdonating car) the pins are connected as (b) (a) 2/3/4/5/7/8/9/10/12/13/15/ (b) 1/2/4/5/6/7/9/10/11/12/14/15/24. Anyone knows where to find a pinout diagram of this system (Bosch number ends with '300')? In the meantime it seems wiring was not consistent in '86 as well... while in my car was one 7 pin connector to the partial loom on the engine block (to injectors and temp sensor) in the donor car where two connectors (4 pin and 6 pin) confusing me. So questions are: anyone got a wiring diagram describing the situation under the hood of my car? My old wiring loom gives erroneous results, ie when nothing connected to the loom between some pins of the EFI multiplug some several 1000 ohms connections can be measured, which can not be correct, there should be either shorts or open lines.   Gábor: The differences are rather small, the main items are the same on four or five diagrams I have, covering lots of different cars from BX to CX, including Peugeots as well. The differences are mostly in the earth pins and are often even interchangeable. The best solution is to have a pencil and a paper and figure it out for yourself - only then you can be sure. And it won't take more than ten minutes. Be sure to bring along long probes and clips. The best way to probe connectors is to push an appropriately sized pin into the receptacle and clip the probe to this pin. Simply place a rag beneath it so that it won't touch anything metal. As you suspect shorts, disconnect all connectors (there are only five or six, including the AEI). Connect to the first pin of the AFS connector, then check on the ECU plug where you have connection and also check that none of the others make a match. Note it, then go on to the next sensor pin. When you went through all of them, check the positive feed and earth to the computer. By this time, I guess, you will have all pins identified. Most of the pins you listed under (a) and (b) coincide, so they will probably come out right as usual:
ATS/AFS: 7, 8, switched positive 9, earth 5/13
TS: 2, 3, switched positive 9
CTS: 10, earth 5/13
Injectors: 12, switched positive 9
OS (but you don't have that, do you?): 20, earth 5/13
Injection relay: 4, 15, sometimes 1 (this is where the ignition connects as well). Even better, now I realize, you have the new loom in the hand, don't you? Then it's a child's play! By the way, when you have already identified the pins, make sure to check all earth points and check whether there is any significant resistance between them: bad earthing can cause many ugly problems. Note that many components receive their earth from different points: injectors, CTS are earthed to the engine, AFS, TS and relay have it through wires. If they do not receive the exact same treatment, they complain violently.
  Scott R: The engine is connected to the frame somewhere by a braided strap or large wire. Find that and make sure this ground lead is in good order and that the connections at both ends are tight and corrosoin-free. As Gabor has pointed out, different parts of the system find their earths at different points, some on the engine and some on the chassis, so a flaky earth bonding lead would cause lots of confusion.
  Harry S: If your air intake manifold is cracking at the seams the plastic is probably failing. I would check it when it is hot. It is likely that the vacuum in the manifold is collapsing the structure and stressing the joints till they crack. If you rev the motor a little (which will drop and raise the vacuum) you may notice the manifold flexing when it is hot.
  När problemet var löst beskrev Marc B hela historien på sin hemsida:
One day the engine stopped and refused to start again. Thus roadservice was called. According to them, the cylinder head might have been damaged. The car was brought to a nearby Citroen dealership and diagnosed. Nothing was wrong with the engine mechanically, but what was the case then? There was ignition, even though the sparks were weak. Replacing spark plugs, spark plug cables, coils and the complete ignition ECU could not solve the problem thus it had to be found somewhere else. Next to check is the fuel, but that seemed to be dosed. However, too much fuel is a problem as well. The injectors were open continuously drowning the engine. With a big hose clamp around the fuel line it would run 'fine', but this was not as it should be. Thus a problem was expected with the injection ECU, found in the front passenger footwell, under the glove compartment (picture right).
  However, the computer was OK (another GTi Auto ran fine with it) and thus it had to be the wiring. Well, that is obvious on a CX - apart from rust all other problems originate from wiring. The cabletree was removed from the car which is a very straightforward job: just unclip all connectors and free the looms from all clips and tie-wraps holding it. Then remove the glove box and gain access to the injection computer in the passenger footwell. Disconnect it and push the big connector through its opening in the firewall. The complete wiring loom was taken inside for testing (right picture). The corresponding wiring scheme is given on the right. It turned out that there was a short circuit on the little piece of wiring connecting the injectors, the auxiliary air valve and the engine temp. sensor to the computer. Replacing the wiring loom should result in a working car. However, it turned out that there were several different wiring looms available for this type and build year of car and that of course the first wiring loom I fitted was the wrong one. So with help from a friend finally the right wiring loom was found and installed and after a month of looking at a stranded car the CX was on the road again!
   The injection wiring loom is a bit tricky. Remove the spare wheel, unclip everything (labeling what is what, but most speaks for itself. See picture on the right. Undo the power supply at the black block near the battery, undo the timing signal from the ignition computer, unclip all injectors and the temp sensor and roll up the wiring loom to the right side of the car. You will need cutting pliers to cut the tie-raps that keep the loom tidily attached to body parts. Then work from front (throttle pos. sensor) back (passing Big Blue and AFM) to end with everything loose at the place where the loom disappears in the firewall to go to the computer. Open car, loosen computer and undo multiplug. Now from the engine side you should be able to pull out a rubber block with an opening plugging a hole so big that the multiplug can be passed through this. Now you have the whole loom in your hands, and you can either proceed to test or to swap. The connector under the spare wheel connecting the main loom to the subloom connecting injectors and temp sensors comes in several different sizes (7, 8 or 9 pin) so when swapping with a loom for a donor car, swap everything, not just the main loom until this connector. You might end up having to rewire a matching connector... :-( or get back to the donor car in that far away junkyard to get the rest of the loom...
   If there is no spark but a fuel smell, that is not good. As you can see from the wiring, the injection is triggered by the ignition. If there is a fuel smell and no spark, something is wrong in the ignition circuit. It definitely should not send the signals triggering the injection without at the same time creating the pulses generating the sparks. So go for a check of the ignition wiring and computer first!
   Order:
1. you MUST have sparks. (otherwise something wrong in ignition)
2. if you have sparks, you also must have gas. (otherwise something wrong in injection)
3. if you have sparks and gas, you must have gas in the right amount, and without air leaks (otherwise still something wrong in injection, or in air supply)
Inprutningsdatorn
Kabelhärvan till inprutningen
Elschema till inprutningen

Startar inte:   Miklos (HU) 2002-01-15:
My CX will not start. What could be the problem?   Alan D (UK): A CX, like any other car, needs: a spark firing at the right time, and fuel in the right proportion. If there is spark, it is probably at the right time, because the timing is fixed by the flywheel 'slug'. The only possibility of wrong timing is if the two spark-coil connectors have been swapped, or the four spark-plug wires have been swapped. Such problems as valve timing slippage do not happen because it is chain-driven, and there is no suspicion of mechanical damage, is there? If there is fuel it will fire unless there is a HUGE amount of fuel or very little fuel. A little too much or too little will not stop it firing. A cause of not firing if there too MUCH petrol is the block temperature sensor. If that is open-circuit or not connected the mixture will be very, very rich - the fuel computer thinks it is very cold, so delivers a huge dose of fuel. In this case, there is fuel and spark but it will not fire. If there is NOT ENOUGH petrol it may be because dirt in the fuel system has broken through the filter and clogged the injectors. They are easily removed and cleaned out. If there is dirt in them, the whole high-pressure circuit should be flushed by letting the pump run fuel into a bucket, after the fuel-filter has been renewed.
  Miklos: The problem with my CX is that it there is no spark. At home I had one extra ignition sensor, so I tried to exchange those, in various combinations, without any effort. The two spark coils (I´m not sure about the english name, the things on the engine to which the spark wires connect) seem to be ok, when the key is turned they get 12V+, when given earth (with a wire) there is a spark. From the above results I concluded that I needed at least one additional ignition sensor to try, which I got by now, just didn´t have the time to put in yet. In the meantime, someone took a look at the Big Blue relay, which seemed to be working ok. Plus, while I had nothing else to do, I took off the air filter to check for dirt. Turned out that only three of the four screws were there to secure its cover and that the rubber sealing on its edge was ripped (hope this is the right word) so needs replacing. By the way, it is the "square type" air filter as I have seen "round ones", too, I don´t know which model had which kind. Needless to say, I blasted out the air filter so it can go back now with new sealing. One other thing I found while fooling with the air filter was that the pipe that connects between air filter and intake plenuum (the piece that looks like a vacuum cleaner pipe) had a hole in it which I temporarily fixed with some tape. While doing these work I treated (well flooded, really) with contact spray all electric connection I came across. Right now the car still sits in the backyard with air filter housing, headlights, etc. spread in the interior. The block temperature sensor, where might that be? I think it could be of use to take a look at that too, as the spark plugs had black deposits on them, as if the car ran too rich. (That could also explain the rather high fuel consumpion I measured in Sept-Oct)   Alan D: The block temperature sensor is at the right end of the block (looking from the driver seat) and is near the injectors (it could almost be injector number 5!) The ignition sensors only fail in only one way - they go open circuit. This is easily checked with a meter, and if it is not open then the engine will start. But sensors which are OK when cold may go open-circuit when hot. Check them with a meter while they are in boiling water. The resistance should read between 50 and 80 ohms, because many cheap meters are inaccurate. Any sensor with this resistance should at least start the engine.
  Marc B (NL): First of all, you should have a spark. The ignition triggers the injection computer, so if the ignition is on strike, you will have no fuel either.
So now: the flywheel sensors are OK. Now does the starter motor make the engine turn over quick enough? Try with *good* jumper cables from another car with running engine. If it runs now: suspect battery and charging voltage, and clean battery connectors very well. If it doesn't run and gives no spark: proceed to test the ignition coils (although I seem to remember you tested those already). Then check all wiring of the ignition, and if possible borrow a working ignition computer from a friend and try after swapping. That would show if the computer is at fault (usually it is not...)
  Gary M (US): I think everyone here knows from experience that the black boxes on the CX are almost never the problem. Wiring or sensors are the problem almost always - or relays. If you can trace the circuits and go direct to check the function, then introduce the other components one at a time or substitute others for them from a working car, you can isolate the problem to a part of the wiring.
  Miklos 2002-03-17: I still didn't manage to get my beloved CX to run. Actually I didn't spend much time on the car and when I finally decided to check out finally what is wrong with the car the weather didn't allow being outside and taking the car to pieces.
Ok, I get to the point: You might remember me writing that the engine won't start (25 injection), that is the starter turns the engine, there is gas but no spark. The hoses coming from the air filter have been cleaned (I don't think that had much effect/sense), all electric connectors have been cleaned, battery charged a few times, the ignition sensors are apparently ok, their wire connections to the "black box" underneath the glovebox are ok, as well as all other wires that connect there, BUT! When testing the connections we encountered this: When starting, the Big Blue relay works, but on one of its pins, (the one coded TD) comes only +3Volts of current. This is the wire that connects to the black box underneath the glovebox and to somewhere else - I don't have the circuit diagrams and I don´t remember right now...
Anyway, I along with the people who helped me working on the car think that this might cause the problem as the 3Volts seem a bit low=easy to get lost in the wiring and connections.
So, the question is that am I right and the Big Blue is faulty or the problem is still somewhere else? I am asking this to make sure the relay is fault because it costs 91 euros to order it and for me it is a big sum to spend, especially when it wasn´t broken in first place. Could anyone check in your own car how your relais work? I think that would be a great help for me. Or has anyone any other ideas what could be wrong? I would appreciate your help.
I wanted to get an update on my progress of the last two weeks in repairing /finding out what´s wrong with/ my cx... The big thing is nothing really happened - I gave the number of starter ring teeth along with a short description of how the ignition is supposed to work (sparks in two cylinders at once, etc.) to my dad, who then told the repair shop. Before you get upset - I was and still am abroad so I couldn´t go to the place myself, it is tomorrow that I go home first time in two weeks...
Anyway, the (checked? repaired?!) black box should be at home now or at least ready to be picked up and paid. The guy there told me when I took the box to them that they will come to my place and put it in the car and check if it works or not. I honestly am excited what the guy will do if it still won´t start...
Ok, I am getting boring here, now to some things I missed to reply to: Marc, I am positive I got the ignition box to the repair shop, the silver injection box is left from the steering wheel well hidden under the dash, and in the engine compartment above the battery underneath the horns there is no box on mine just a black plastic cover with a couple of relais underneath it, so in my car the ignition box is(well, was) underneath the glovebox...
CGAT, thanks for the offering but I have no idea how it would work to send all that stuff to the UK, but it is always good to know that when nothing else works I have a last option :) (Well, the last option actually would be a steam roller but I know I would regret that...)
  Johan G: Find the layout for the engine wire loom of a single sensor GTi at http://www.algonet.se/~frenchie/cx/CXtech.html
  Marc B: Don't suspect the computers too quickly. On my GTi, with a comparable problem (sudden death, no possibility to wake her up at first, and nothing obviously wrong: sparks, smell of gas from the exhaust and no air leaks) finally it turned out there were some shorts in the injection wiring loom. Injectors were shorted and thus permanently open. She would run with a big clamp squeezing the fuel supply line almost shut... Anyway, bottom line of this: even with a short circuit and lots and lots of tries to start it the computer still wasn't broken. It worked fine in another GTi when doing the swap test and after fixing the wiring worked fine everafter...
  Miklos 2002-05-02: I am glad to announce that my CX is now up and running. And it wasn't the Big Blue, it wasn't the wiring, not the coils nor the sensors... It apparently WAS the black box, the ignition computer which I got back this afternoon. The guy from the electronics shop who brought it home told me that the people who actually repaired/tested it (two different companies) re-soldered pretty much everything in it although nothing seemed loose. Anyway, after it was put in the car started by the first turn of the key - wow! I guess you can imagina how happy I was today... After putting the various parts I took of the car while attempting to check and repair back to their places, taking some pictures (of the huuuuuge puddle of ATF underneath her) topping up the gearbox I took her to the car wash and then a ride around town I feel great - the ride is great, people are staring at the car, life is great. Thank you to everybody who helped me with their ideas and tips and I wish you safe and trouble free rides in your CXes!! / Mike(HUN)

Svårstartad: Till toppen av sidan
Svårstartad och går inte på tomgång:
  Lerager 2005-07-28:  Min T2 er sværtstartet, og kan ikke gå i tomgang før den er rigtigt varm. Når den er blevet varm, går den meget ustabilt i tomgang. Jeg har først lige købt den, og ved ikke hvordan den er blevet vedligeholdt.
Jeg vil gerne lave en tjekliste til de dele jeg skal undersøge:
1. Skifte tændrør
2. Rense tændkabler
3. Rense irrede stik på følere/givare
4. Rense luftfilter
5. Tjekke for tyv-luft i slanger
6. Tjekke hjælpeluftventil
7. Tjekke luftmassemåler
8. Tjekke tændspoler
9. Tjekke ECU
Er der nogen forslag til hvad man kunne tilføje til listen, eller ændring i rækkefølgen?
  Jonsto:  Det første jeg ville ha gjort er å skifte bensinfilteret! Så ville jeg ha satt luftfiltret som nr. 3. Punktene 1, 2 og 3 bør da gjøres samtidig.
  Lerager:  OK. Men den har ingen problemer med at tage omdrejninger, og den sætter heller ikke ud ved høje omdrejninger. Er der nogen særlig grund til at det skulle være benzinfilteret der giver ustabil tomgang?   Jonsto:  Nei, egentlig ikke, men man skal aldri være for sikker når det gjelder disse bilene. Har hatt et par tilfeller med ustabil gange og fusking enkelte ganger der det har hjulpet. Min 85 GTi Turbo begynnte å bli tungstartet. Den ble OK etter skifte av luftfilter. Personelig har jeg som regel at når jeg kjøper en ny bil for å bruke skifter jeg: bensinfilter, luftfilter, plugger (tændrør) og olje m/filter.

Svårstartad vid kall motor:
  Kai 2002-01-13:  Jeg har nå begynt å få veldig problemer med min CX TRi. Den starter ikke når den er varm, hoster og harker mens den går. Turtallet ligger da på 1000-2000 omdreininger.   Jan M: Jeg er mer usikker på hostingen og harkingen din, men det kan være luftmengdemåleren som sitter bak høyre frontlykt. Hvis denne er defekt vil motoren kunne opptre som du nevner, og gjerne ha et svært høyt bensinforbruk.
  Børre H: Kan være temp føleren. Sitter på venstresiden av toppen i bakkkant sett forfra. Ser ut som en injection plugg. Denne bestemmer hvor mye bensin han skal få ved div temp. Typisk om termostaten din er kaputt. Vil få kaldvannsstrøm fra radiatoren, og vise feil. da får motoren for mye suppe, og ryker svart. Skal være ca 5000 ohm ved 0 grader, og 300 med skikkelig varm motor. Jeg har kjørt med en vanlig motstand kjøpt hos en TV reparatør for 5 kroner som jeg plugga i pluggen. Billig diagnose, men ueffent ved kaldstart. Sjekk bagatellene først - men, jeg er jo tilbøyelig til å tippe på svinghjulssensorene.

  Gustaf 2001-12-03: När temperaturen går under +5 är det som förgjort. Startkabelhjälp är ett måste. Ett samtidigt fenomen är att det inte är tillåtet att köra för kort. Dvs om man stannar innan motorn är uppe i normal arbetstemperatur så går den inte igång igen förrän den fått svalna någon timme. Jag har en CX25 -88 och den Haynes jag har stämmer inte, dvs jag har inget extra kallstartsmunstycke eller också sitter det på en lurig plats. Några tips från den kunniga läsekretsen?   Jerker B: Hade nåt liknande problem på min CX 25 Gti -88. Den gick väldigt orent, svårstartad osv. innan den kom upp i arbetstemp. Och dog den, fick man vänta tills den svalnat. Det visade sej vara lambda sonden. Kanske kan det vara den som spökar hos dej. Jag tog bara isär anslutningarna vid batteriet, sen gick den fint.
  Jens: Två saker, antingen lufsliden på baksidan av motorn eller svänghjulsgivaren. Troligtvis båda.

  Alasdair 2001-01-22: Been having problems with my '82 2400IE recently. Last night it almost refused to start, and then ran roughly at idle. It seemed to have very little power at low revs, and at one point it stalled several times. Each time it stalled it would restart OK, and would rev smoothly when I pressed the accelerator, but when I put it into gear it would stall again. Once I got the revs up it seemed happier, and as soon as it warmed up it ran smoothly. Recent postings suggested that an air leak might cause problems at idle, but my problem seems to be temperature related. I don't think it's the cold-start injector, as that would merely make it difficult to start. It sounds more like a problem with the temperature sensor, and the mixture not being rich enough for cold running, but I can't see any reference in the Haynes manual to checking this, except to say that if you unplug the temp sensor lead when the car is hot it should stall (???). Any ideas?   Neil H: Had the same thing with a 25 prestige. It turned out to be a porous hose connecting the air flow meter to the throttle body. Symptoms were, difficulty starting from cold, erratic idle when it did start, free revving when warm but stalling when drive was engaged. Open your bonnet and sit in the car, start the engine. If you have a good hand brake pull it on or chock the wheels. Engage a forward gear (make sure the front of the car is clear of things you don't want to run down) GENTLY using the throttle and clutch (Brake if Auto) take up the drive. Looking through the gap under the bonnet, see how much (if at all) the engine moves up and back if it so does the engine cut out then? If so this is a sure sign that the engine mounts are weak and possibly pulling open the concertina part of the connection hose from the airflow meter to throttle body thus air isn't drawn past the meter so the fuel is cut and the motor stalls. Alternatively you could just take the hose off, inspect it and not prat around as I have described to eliminate this possible cause.

  Doc M 2001-01-23: Har i vinterkylan fått allt trögare att igång tändning på min CX T2-88. Startmotorn kan behöva gå 1-2 min innan motorn hostar igång - med startkablar.   Maurizio: Felsökning:
1: Kolla reläkontakten på det blå reläet under höger framlykta.
2: Kompressionen kan vara dålig, men då borde du märka det med blårök.
3: Kolla luftfiltret, på en av mina var det så igensatt att den nästan var omöjlig att få igång.
Går den rent när den väl är igång? Gör den inte det, kan det även vara luftslangen in i motorn, något litet hål på undersidan kanske.
  Henrik: Motorvärmaren kan vara orsaken. Har man den inkopplad en kort stund så lurar den insprutningssystemet att tro att det är varmt och skönt ute = det blir fel bränsleblandning. Det sitter nån sensor nära värmaren.
  Annika: Efter 10 år med vår T2-87 i klimat norr om polcirkeln så har jag ett och annat att tillföra om startsvårigheter på vintern... Har tidigare skrivit om vikten av ett fulladdat batteri, installerade en kontinuerlig laddare som går på när man använder motorvärmaren. Om startmotorn får dra runt länge så kan det också enligt egen erfarenhet bero på jordfel. Motorn klarar av att starta om det är varmt och fint, men behöver lite mer kräm för att dra igång när det är kallt, och ett jordfel kan göra att du inte får ström så att det räcker för att starta. Jordfel verkar vara ganska vanligt, och byte av jordkabel kan behövas då och då.

Svårstartad med motorvärmare:   Fredrik 2001-02-10:
Suck... varje vinter likadant. Min CX T2 -88 startar inte när motorvärmaren har varit inkopplad mer än ett dygn i sträck, ja ger man den startgas så går den förstås. Problemet blir då istället att batteriet (tillsamans med den norrländska kylan) inte pallar alla startförsök utan startgas och vips så finns det inte tillräckligt med ström. Funderar, som varje vinter, på om det finns någonslags chokefunktion som inte fungerar eller om det kan vara dålig kontakt någonstans?   Mikael: Ditt problem beror troligen på att motorvärmaren sitter monterad alldeles intill givaren till kallstartsystemet. Jag har samma problem om jag har motorvärmaren i för kort stund. Men samma symton kan nog uppstå om det är rejäl kyla. Värmaren sitter i topplocket och orkar inte värma hela motorn men givaren indikerar att den är varm. Till dieseln finns en värmare som monteras i motorblocket - den borde även passa till bensinaren.

  Alfred 2001-12-07: Jeg vet vi har hatt dette oppe på CX-akuten før, men jeg har ikke sett at noen har gitt andre løsninger på problemet enn kald start. Problemet: Hvis jeg ikke bruker motorvarmer, starter min CX Croisette -89 (alias 2,5 injection alias CX25 GTi ikke turbo), uten noen problem. Ved bruk av motorvarmer tar det mange minutter. Idag ga jeg opp og tok Xantia uten motorvarmer. Motorvarmeren hadde vært tilkoplet i ca en time, og ønsket var først og fremst å benytte kupevarmeren. Men, hva kan jeg gjøre for å få problemfri start med motorvarmer i bruk?   Mikael: Jag har haft samma problem och det beror på att sensorn till kallstarten sitter bredvid motorvärmaren. Om jag hade motorvärmaren i en kort stund så var bilen helt omöjlig att få igång, det enda som hjälpte var att koppla in värmaren en längre tid så att hela motorn blev varm. Det finns två typer av värmare till CX, den ena är monterade i toppen och den andra monteras i motorblocket. Den senare fungerar bättre då den värmer hela motorn.
  Tore T: Jag hade samma problem med min CX T2 förra vintern och ett "trick" som verkade hjälpa var att först slå på tändningen - men INTE starta - och låta det vara så i kanske 10 sekunder (t.ex. medan man tar bort sladden till värmaren). Sedan kunde man starta utan problem. Den enda förklaringen till det här torde vara att man ger styrdatorn en chans att "läsa in sig" på värdena innan man påbörjar start. För övrigt håller jag med Mikaels inlägg om att det blir mindre problem om hela motorn är genomvarm, dvs. att värmaren stått på en längre tid.
  Thor Ø J: Jeg har hatt mye problemer med dette, men det er nå helt borte!! jeg har byttet og sjekket alt som har med "mellomvarm" motor å gjøre: temperaturføler, tillegsluftventil, sjekket luftlekkasjer nøye etc etc. Nesten alle motorer har lettets for å få startproblemer mår de er litt varme.

Svårstartad vid varm motor:   Anders Ö 2001-09-09:
Varför är min T2:a svårstartad när den är varm? Har bytt tändspolar, tändkablar, pulsgivare, sprayat kontakterna med elektospray m m. Jag nöter på startmotorn ca 20-30 sek, men efter en stunds nötning så startar den. Symptom ungefär som att den är sur....   Lars H: Ett tips kan vara att kontrollera att huvudjordpunkten för batteriet på växelådan är ren och fin. Kontrollera också att kallstartventilen inte är öppen när du varmstartar, då blir den lite sur.
  Mikael: Det finns ingen kallstartventil på CX efter -85. Men kolla givaren till kallstarten som sitter i toppen vid höger hjulhus, motorvärmaren kan sitta på samma ställe. Jag är inte säker på om den bryter eller sluter vid kallstart men det kanske någon annan vet. Den skall iallafall inte ge samma signal vid kall som vid varm motor.
  Anders Ö 2001-09-09: Varför är min T2:a svårstartad när den är varm? Har bytt tändspolar, tändkablar, pulsgivare, sprayat kontakterna med elektospray m m. Jag nöter på startmotorn ca 20-30 sek, men efter en stunds nötning så startar den. Symptom ungefär som att den är sur....   Lars H: Ett tips kan vara att kontrollera att huvudjordpunkten för batteriet på växelådan är ren och fin. Kontrollera också att kallstartventilen inte är öppen när du varmstartar, då blir den lite sur.
  Mikael: Det finns ingen kallstartventil på CX efter -85. Men kolla givaren till kallstarten som sitter i toppen vid höger hjulhus, motorvärmaren kan sitta på samma ställe. Jag är inte säker på om den bryter eller sluter vid kallstart men det kanske någon annan vet. Den skall iallafall inte ge samma signal vid kall som vid varm motor.

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Låg tomgång vid kallstart:   Cristi 2000-09-18:
Can anyone tell me why my car in the morning when I start it, stays at 500-600 rpm and after it warms up it's ok it stays at 950 rpm. It's a CX 25 GTI Turbo 2 and it doesn't have a so called cold starting injector at the end of the admission gallery.   Alan D: Possibly sticking extra-cold-air valve on back of block, low down where it is almost impossible to get at. It has two air-pipes and one electrical plug. When it is cold there is a large hole connecting the two air tubes. This 'opens the throttle' a little when cold. It warms up by electrical heater and engine heat to close the hole.
  Gabor: There are two component responsible for the warming up (after the initial 30 sec period): the auxiliary air valve and the coolant temperature sensor. If either the valve is closed on start (it should be open when the engine is cold and then close gradually) or the CTS gives an erroneous signal, the computer is fooled to think that the engine is already warm enough and injects less fuel than necessary.
The sensor is easier to check if you have an ohmmeter at hand (you can find the correct resistance values on my site, Fuel/Injection/Testing). If it is OK, the valve can be checked almost as easily but you'll have to remove a few hoses.
Gabor DEAK JAHN -- Budapest, Hungary. The Citroën BX Do-It-Yourself Site (with XM Pages): http://argus.vki.bke.hu/~djg/bx/
  Alasdairs: My injection CX was behaving exactly like a carburetted engine when you push in the choke before it's warmed up properly (=tends to die at idle, but wakes up at high revs.) I was wondering if it had something to do with the temperature sensor failing to report the correct values, so that the mixture wasn't getting enriched when the engine is cold.
Now the problem seems to be solved. When I took off the connector to measure the resistance of the temperature sensor, I found that the values were ok. I put the connector back, and the next day is started perfectly, and has behaived ever since, so I assume that it must just have been dirty contacts between the sensor and the connector. Odd, becasue I jiggled the connector around and moved it back and forth a few times when I was originally checking all the wiring, but it must have been the act of removal and disconnection that did it.

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