AX Help!

Ian Fearn · Post by **Ian Fearn** » 13 Jun 2005, 23:33

Got a problem with a 1.1i AX. The car WAS running fine yesterday.
Today when trying to start the car the engine management warning light has come on and the car wont start? It will turn over however.
Any ideas?

Post by **CitroJim** » 13 Jun 2005, 23:54

Coolant temperature sensor. Crank position sensor. Fuel pump and relay, Ignition coil(s). Bad connection somewhere. Fuse...
Check have you have a spark and have you fuel being injected (wet plugs and fuel smell when trying to start)... One or 'tother or both will be missing.

Ian Fearn · Post by **Ian Fearn** » 13 Jun 2005, 23:56

Havent yet checked for a spark or fuel.
Do you know where the fuel pump relay is on an AX?
Would the crank position sensor stop it from running?

Post by **CitroJim** » 14 Jun 2005, 00:55

No Ian, I'm afraid I don't. The last AX I owned had a carb...
The info in my last post is pretty general as I'm a dieselhead really and is based on my learning of how my 205 GTi Bosch LU2 Jetronic system worked.
Pump is easy to check. Ignition on and listen for it whirring in the tank. It should whirr loudly for a moment as it build pressure and then just quietly hum.
Yes, indeed, the crank position sensor will stop it running as the ignition system looses it's timing reference and will not spark.
The coolant sensor can also cause the engine not to start by not richening up the fuel for a cold start. can be checked by using an ohmmeter (Multimeter) to check it's resistance. It should be somewhere in the region of 800 Ohms and this will vary depending on temperature but if it's open or short circuit it's duff.
Hope that helps a little bit Ian. Apart from the ECU itself, I don't believe there is a lot else that can cause a total start failure. Many other things will make it run roughly but I think those are the showstoppers as it were...

citronut · Post by **citronut** » 14 Jun 2005, 01:07

try not to crank over to much if fuel is going through system as you wont do the cat any good at all pumping unburnt petrol into exhaust,thats if it has a cat regards malcolm

Post by **martyhopkirk** » 14 Jun 2005, 01:17

Its a vague possibility it could be something major like a timing belt.
I would be looking at the electrics in the ignition circuit being broken or a duff connector.
The ECU is located in the engine compartment on the Right hand side under a black placky cover.
The fuel relay is cliped directly to the underside of the ECU mounting plate.
InMyHonestOpinion the best fix for an AX is an oily rag and a lighter....

citronut · Post by **citronut** » 14 Jun 2005, 01:50

ooooh bitchey

Post by **martyhopkirk** » 14 Jun 2005, 03:05

Speaking from bitter experience with my AX Malcolm.

JohnT · Post by **JohnT** » 14 Jun 2005, 05:44

Until u check for the most obvious, is there a spark and fuel? stay with the basics before going for the technical stuff at this stage? I agree with citronut, you can incur the cost of a new cat if you continually wind it over with excess fuel being unburnt. I like to keep things simple in diagnosis. Its often a simple answer to the problem. Keep us posted on the outcome.

JohnT · Post by **JohnT** » 14 Jun 2005, 05:48

One idea? Has your alarm system caused a problem and immobolised the car? Just a thought.

Ian Fearn · Post by **Ian Fearn** » 17 Jun 2005, 00:53

Thanks for all your help on this chaps.
I did a fair big of digging to try and highlight the problem all to no avail.
I found no spark and no fuel being pumped through. So I decided to hit the ECU with a fault code reader.
The ECU only sends a signal to the fuel pump when it detects a pulse from the spark. So no spark = no fuel.
The fault code reader told me the system was fine so i proceeded with the fault code reader to re-set the ECU. After this the dash light extinguished itself and the car started first time and has started on subsequent times.
By the way, the car does have an immobiliser but no alarm. It seems to isolate the starter motor though and this was turning over fine.