Help needed with misfire

[brm180]

Hi folks,

Now and again the S2 (aby) would run like it was on 4 cylinders. My mechanic has changed out coilpacks, swapped over injectors, checked all wiring etc etc and it is always no 5 Cylinder that is faulty no matter what is changed out or tried . He is now pointing me towards Main Stealers as he thinks it may be a faulty ecu (£££'s) and he is at a loss at what to try next. Any help ???


brm180

[GazzaG60]

have you checked the POS. have you tried swapping over the plugs of the 2 to see if the issue moves.

[brm180]

misfire

Hi,

yes he has tried the pos and changed over all the wires. I even down-loaded the SJMautotechnik link with all the options available, but it is still cylinder no 5 that is at fault...???

Any ideas..


brm180

[Jamo]

Find a forum member near you, test your ecu in their car and vice versa

[brm180]

misfire

Hi folks,

just picked up the car this morning and i'm going to book it into the electrical specialist Garage.
My mechanic also told me that it pulls up the following message on the Vag Com..
engine rpm sensor.. everytime he clears it it then comes back. Any link to the misfire ?


cheers brm180

[red leader]

Might be a faulty tappet?

[irishs2]

Compression test on no.5 compared to the rest wet+dry ? maybe

[driftin jo]

Hi folks,

just picked up the car this morning and i'm going to book it into the electrical specialist Garage.
My mechanic also told me that it pulls up the following message on the Vag Com..
engine rpm sensor.. everytime he clears it it then comes back. Any link to the misfire ?


cheers brm180

Is he retrieving fault codes it with the engine running ?
if it is not running it always throws that code, test with Vag Com with it running.

[chipsenter]

I suggest to replace the speed sensor if so, its not so common actually . I had the same problem on mine though , it doesnt need to be the sensor if vag-com register this error code anyway. hows ur LMM doin ?
Is car chipped or stock by the way ? what sparkplugs are u runnin ?

[UrS4boy]

....My mechanic also told me that it pulls up the following message on the Vag Com....engine rpm sensor.. everytime he clears it it then comes back. Any link to the misfire ? cheers brm180

You will always get a engine speed sensor code if the engine is off when the codes are pulled so I doubt that that is the real problem. Here is some G28 engine speed sensor info:

http://forums.audiworld.com/showthread.php?p=18839940

Rather than let your mechanic tell you what he thinks *might* be the problem, I suggest that you get your hands dirty and start at square one (so you know yourself what is going on), following this missing and hestitation diagnostic procedure:

http://forums.audiworld.com/showthread.php?p=18838360

[brm180]

misfire

Thanks for the above links. I'm going to download them and try and have a look myself.
The car is totally standard, the plugs were fitted at the dealership and have done approx 15000 miles. The problem is intermittent. It would be okay then i'd lose a cylinder then it would clear itself after the engine was switched off. Even driving, the car would be ok then i'd lose a cylinder then it would clear itself. It's like a wire breaking then making contact again. Not sure if driving over pot holed roads would damage connections or not. When i drove the car to my mechanic all was fine. He drove it for two days and all was fine, then it lost a cylinder and hasn't recovered since.

brm180

[karlblues2]

I know it sounds too obvious, but have you actually swapped out the spark plug from cylinder 5?
Cheers
Karl
Oz

[brm180]

misfire

Hi Folks,

On starting the car today it roared into life on 4 cylinders then cleared itself after 5 min and run perfect. When i got home i parked up and left it for approx 3 hours then re-started the car. It started on 4 cylinders again gave a couple of coughs and cleared the misfire. On driving the car it seemed a little rough but again cleared itself .
Not sure what to think now.


brm180