A3 juddering problem :( Help needed by the audi brainers

[L3WJX]

Would like help with any body who has had this problem or no of anybody who has fixed this,

I have a 1998 Audi A3 1.8T petrol (AGU engine) the car has just done 123,000 miles
I can be driving along normally then for no apparent reason when I accelerate the car hesitates and feels as if its missfiring,this was doing it about 4months ago then stopped and now has come back and is a real pain in the a** to drive help would be great

It lasts for varying amounts of time then disappears. When the car is stationary with the bonnet up I can see the engine appear to misfire causing it to jerk every so often causing a popping/spluttering noise from the exhaust. This doesnt always happen so cant put my finger on what it is.

A couple of times I have been sat at lights and the revs drop to almost stall point but then it corrects itself. last week it was really bad,

I have had a new maff fitted about 5 months ago so hope it is not that,also things i have done to my car full servise 8,000 miles ago,exhaust cat back,piper-cross panel filter,remap and 007p d-v,

Would be great if any body could help me on this thanks alot

 

[<tuffty/>]

VAGCOM (VCDS) in the first instance to see if there are any fault codes...

There are a couple of possibilities here... air leaks (vacuum/boost) and ignition.... when was the last time the plugs were changed? I would also check the gaps... should be 0.7mm...

Could possibly be a coil pack but they just normally go and stay gone... I would check for vac leaks (more likely at your mileage) and check the plug gaps (assuming they have been changed recently)

Pipes usually split under the inlet manifold... PCV being the favourite as they carry oil and it rots the rubber...

Get fault codes checked first though...

<tuffty/>

 

[L3WJX]

No fault codes showing,no leaks i can see as boost gauge showing the same? millage didnt think it was that bad ???

Allso been told could be the ignition on side of air box,could this be the reason ?

 

[<tuffty/>]

Could be... there is an ignition amplifier pack on older A3's thats attached to the airbox... could be that...

<tuffty/>

 

[L3WJX]

Ok will give that a clean tomorro thanks

 

[talentwalsh]

No 1 coil went on mine and caused similar problems but it was really bad. Horrible spluttering, misfiring and the likes. The coil was actually popping out its seat and causing the engine to run on 3 cylinders. Could this sound similar?

 

[DaveA3]

i had the same thing on friday it was my ignition control module. changed it in 30 seconds and problem went away. coilpacks rarely go on AGU's. The ignition control module cost me £69 from eurocarparts. They call it just "ignition module".

Cleaning it wont help by the way. but u can keep the original heatsink aswell. Just be careful not to knock it on anything when fitting its quite sensative. i put some of my cpu thermal paste between the two aswell for extra cooling.

hope that helps

 

[Welly]

OK.

I'd go with the ignition output module also.

It's called the Power Output Stage module N122 (p/n 8D0 905 351 (A4) or 4D0 905 351(A3))

There is a guide for testing them here:
DIY test of power output stage/ignition amp module N122 (long & BWW) - AudiWorld Forums

 

[L3WJX]

Thanks guys will look tonight when I get in for a new one thanks alot

 

[Elitecarz2011]

can you remove this ignition module as my car is causing similar problems, can I not just put a induction kit on

 

[xxxxSMITHYxxxx]

See this sounds like the same thing that is happening to mine ATM, so will it be coil packs or ignition amp, plugs just been font on mine, also do u get a bit of a strange start when first turning the car ova?

 

[<tuffty/>]

can you remove this ignition module as my car is causing similar problems, can I not just put a induction kit on

No... you can't just remove the ignition amp... if its faulty you need a new one..

<tuffty/>

 

[Yonner]

Try unplugging your MAF , it will throw lights on dash but they will go when you plug it back in , mine was the same , I unplugged MAF and drive the car , it wouldn't boost much but drive very smooth through all gears , as soon as I put new MAF on and all was ok !

 

[Elitecarz2011]

Starting the car is fine. it doesn't judder on a start engine and does it a lot on motorway, it feel like its loosing power, Iv been told its ignition module because its not getting the right air in.

Iv already spent a lot of money on this car and its been a beauty, my mechanic also cant figure out, and iv got everyone saying all sort.

Coil packs, ignition module/amplifier, it need a remap.

Don't know what to go with...

 

[Jason Reed]

i had the same thing on friday it was my ignition control module. changed it in 30 seconds and problem went away. coilpacks rarely go on AGU's. The ignition control module cost me £69 from eurocarparts. They call it just "ignition module".

Cleaning it wont help by the way. but u can keep the original heatsink aswell. Just be careful not to knock it on anything when fitting its quite sensative. i put some of my cpu thermal paste between the two aswell for extra cooling.

hope that helps

I have the same sort of problem only my IGN AMP is loose in engine bay as I have a ram air induction kit fitted when you say they break how do they brake and can they be repaired

 

[<tuffty/>]

I have the same sort of problem only my IGN AMP is loose in engine bay as I have a ram air induction kit fitted when you say they break how do they brake and can they be repaired

You fix it much like this...
http://uk-mkivs.net/topic/51078-repairing-bosch-4d0-905-351-icm-unit/

...but just buy a new one... its less hassle

<tuffty/>

 

[Jason Reed]

Ok then cheers bud