1999 S3 running lumpy

[S3PEG]

I've put up with this for a while but it's got to the point that it's doing my head in.....

at tick over the engine coughs and does the same when maintaining speed or pulling away (both using low revs) under accelleration or breaking the engine seems fine - no coughs or splutters til I come to a stop and the engine returns to tick over.

No fault codes on the ECU and my local stealer checked the air mass meter/fuel system but reported no problems - I told them I'd leave it to the experts... please don't let me down...!!

 

[voorhees]

Coil pack, Spark Plug,Throttle body or Coolant temp sensor ?

 

[S3PEG]

Thanks - I've recently changed spark plugs and coolant temp sender. I was also thinking throttle body and plan to give it a clean this weekend. Would a faulty/failing coil pack throw up an error code?

 

[s3tle]

Coil pack doesn't always throw a code on vagcom, if you've got vagcom you can log channels 15 + 16 i think. Get a friend to log those chanels whilst you go for a drive and they should see any misfires.

 

[S3PEG]

Thanks s3tle - I'll give this a go.

Just been reading other threads about a secondary air pump - could this come into play here?

 

[karls s3]

i have changed coil packs x4 plugs cleaned throttle body only thing i not done is coolant temp sensor do these really cause engine to run lumpy on idle

 

[richrich14]

Have you checked for splits in the PCV pipework? I had similar issues and has helped solve some of the problem.

 

[s3dave]

with it been a 99 the SAI(secondary air injection) can cause problems and fill with water It can be deleted.....

 

[karls s3]

sorry should have put car is a 2001. on the side of the block near tip there is 3 threaded holes and a hole in the middle with some thing in the hole blocking it. i used to own a ibiza cupra and a egr valve was in this place. didnt know if our cars have one.. engine code is amk

 

[karls s3]

Have you checked for splits in the PCV pipework? I had similar issues and has helped solve some of the problem.

yeah near left of inlet near the valve i had split pipe that i put a hose over with two clamps

 

[s3dave]

sorry should have put car is a 2001. on the side of the block near tip there is 3 threaded holes and a hole in the middle with some thing in the hole blocking it. i used to own a ibiza cupra and a egr valve was in this place. didnt know if our cars have one.. engine code is amk

AMK has an EGT yes
it should be fastened underneath the inlet manni

 

[karls s3]

i know egt is under inlet manifold but not too sure on egr ill have a look also im not sure whats supposed to go on the side of engine where the 3 threaded holes are.

 

[karls s3]

how do you know if the throttle body is faulty is there any way of checking