A4 1.9 tdi ESP light and misfire

[sickboy10]

Hi

I have an 03 a4 1.9 tdi with 155k miles. It has always been a great runner but recently has given a few problems until yesterday when I had to be towed home. The AA didn't know what the problem was so I thought I would ask here.

The last few months it would very occasionally judder for a couple of seconds and then be fine. I had it serviced, had all the filters replaced and they ran an engine cleaner though (although I only had a quarter of a tank of diesel and I think you are supposed to run it through for longer than that?). The problem carried on for a few seconds every few days but then yesterday got much worse. The whole car now judders heavily under idle and does not like accelerating. A few seconds after it started juddering the ESP light came on and is continuous. The engine management light has not come on at all. If I turn the engine off for a few minutes and start it again it runs fine for a few seconds then starts to judder and the ESP light comes on.

Any ideas? The AA suggested injectors or the EGR valve. I wonder if a fault in the ESP is cutting power to some cyclinders? I am going to take it to a garage but want an idea of what it could be before they suggest replacing the injectors!

Thanks for any help you can give.
John

 

[Funkyfin2000]

No one near by who could VAG com scan it for you?

Maybe a MAF ?

 

[sickboy10]

The AA checked and said there were no fault codes reported. Not sure if they can check to the same level as VAG com?

I'm planning to take it to a VAG specialist fairly close to me so I guess they will do a full scan. I have never used this garage before so wanted to get an idea of anything it could be before they starting suggesting things.

 

[paul20v]

Maf wont cause a missfire
at that mileage i would be replacing the injector loom in the head
there around £35 and are prone for a bad connection on no1 injector due to it being the unsupported side of the loom .
and also ive seen the esp light come on with a loom fault
strange but true .

 

[quattrojames]

The ESP light comes on with most random faults on Audi's!

 

[paul20v]

The ESP light comes on with most random faults on Audi's!

The last one that i done was on an octavia but same lump and the esp light came on .

 

[sickboy10]

OK. So I have the car at the garage now and they have just phone to say that VAGcom is reporting a misfire on cyclinder 1 and also a temperature sensor fault (although he doesn't think that is related/causing the misfire). They are going to try changing the injector wiring loom which I agreed to. The only thought I had is that is runs without a misfire for the first 20 seconds or so. If it was the wiring loom wouldn't it misfire straight away?

I'm not sure how the engine management works but I wondered if perhaps it may run on a default setting until it gets data from the sensors. A faulty sensor could then mean that the ECU us doing something strange after a few seconds of running.

Any thoughts?

 

[iyrix]

Maf wont cause a missfire
at that mileage i would be replacing the injector loom in the head
there around £35 and are prone for a bad connection on no1 injector due to it being the unsupported side of the loom .
and also ive seen the esp light come on with a loom fault
strange but true .

Sounds like you might have been spot on! who needs a vagcom.. lol

 

[sickboy10]

I got my car back from the garage a few days ago and it seems to be running fine now. It was the wiring loom after all. I still don't understand why as it ran fine for the first few seconds after starting but hey.....it's fixed so I don't really care!

If anyone is interested I had the work done at GMS Kent in Maidstone. They are only a small outfit but are a VAG specialist and seemed to know what they were talking about.