Audi 80 2.0L ABK engine juddering/misfire

[brd]

Hi all,
I am having a problem with generally intermittant juddering when driving (at any revs) and very rough tickover ... it seems mainly when hot. There is a smell at the same time which I guess is from the catalytic convertor. I changed plugs, plug leads and distributor cap as they were in a bad way, but the problem is still there. I have ordered a new lambda sensor and will fit that in the next few days when it comes.

Any ideas on what else could be the issue? It has been getting progressively worse and now the car is becoming pretty much undriveable.

Any help is greatly appreciated... thanks!!
Brian.

PS: I've seen posts there where people were having trouble with dash lights fuse blowing, reversing/rear fog lights not working, boot light, etc.... the problem is the boot cable on the left hand side at the hinge that bends too much and breaks internally. Change or fix it and sorted. Its a know problem.

[Marc97]

Wait until your lambda sensor arrives. It will more than likely fix your problem (fingers crossed).
If it isn't that, it may be the air flow meter or MAF sensor as it is also known (isn't it?).
Great advice too on your first post, welcome aboard

[brd]

Looks like the engine running problem is finally sorted!

Changed the Lambda sensor last night... straightforward enough. Car runs pretty sweet now. Just need time to tell as the problem was a bit intermittant, but I reckon we're lookin good.

So... all in all, I could see improvements in the problem after changing the plug leads, distributor cap, air filter, plugs, and finally the lambda sensor. I think it was the lambda guy that was the main cause but the symptoms were incrementally getting a little better by changing each of the other parts.

So, if ever you get bucking while driving, whether under load, neutral load or slowing down, rough tickover, really smelly exhaust fumes... and a real pain to drive, particularly in traffic.... and sometimes cutting out when throttle dropping back down to tick-over.... then this is your most likely cause. I also had very carbonated plugs from running too rich and fuel consumption was not great.

A standard service covers some of the parts, but one should consider changing the lambda sensor and plug leads at about 100,000 miles as part of a service. An easy enough job, just a little fiddely routing the sensor lead, but with the car well jacked up, it's ok. The lambda sensor cost 45GBP+shipping (about 70euro) - sourced through the web). For a 1995 ABK engine it is the 3-wire one.

Hope this helps other people out there.. and thanks for the advice.

[Marc97]

Well done mate.

[Timja]

What is a lambda sensor?

Mine is not idling very well, but waiting for a new air pipe from Audi (Been waiting 7 weeks now!!!! ) that goes to the idling control valve as mine has a hole in it!

Audi being useless - Audi UK customer services also as poor as dealer. When i phoned them having got fed up with dealer and having to wait so long, their response was 'to be honest with you sir, your car is more than 10 years old, and we are only legally obliged to keep spare parts for 10 years so may not help you'

Nice.

[brd]

The lambda (or oxygen) sensor measures oxygen level in the eshaust gases. Check this link out for more info:
http://www.autohausaz.com/audi-auto-...i-repairs.html

And I hear you loud and clear about service... got shafted 350 euro for Audi garage to replace plug leads and distributor cap and they said problem sorted.... which it was not. They said the cap was broken (they broke it!) and ignored being told that the smell from the cat was an issue which would have helped source the lambda sensor as the problem. When I started to "fight" back, I got the cliche garage talk pushing any responsibility elsewhere. I've been working with engines long enough to understand the complete twaddle ... but was away and didn't have much option. Unreal.

[brd]

(Update in Audi 80 Avant - Intermittant misfire ? thread - same engine)

Damn problem not sorted... so checking the fuel tank breather idea - as tank always seems under pressure when I open the fuel cap - just not sure of always positive or if sometimes negative... by using a fuel cap that doesn't seal (cheap one)... 110kms so far and no prob ... but as its intermittant, it might be early days.... will keep you posted.

[kbowern]

Could it be the "hall effect" sender which is part of the distributor. Mine failed, but when it did the car wouldn't start. I believe there is a way of testing it, but not sure how.

[marki]

Hi I had the same problem I think. Slight misfire. No fault codes.Changed the plugs and leads. I needed to change the cambelt.Mine has 140,000 on 2.6 V6. The night before I disconnected the battery to reset the ECU.( i think it takes 10 hrs to reset) This is a common method used by the Japs. The ECU can 'drift' as the engine wears and parts are changed. ....It then relearnt itself. Now, in the morning before I took it to the garage I did notice smoother running ! but didn't drive for too long. After the Cambelt change it was still running smooth ! so whether it was a slack cambelt or the ECU reset the car is running much better ! It was very annoying before.....intermittent juddering / coughing at all revs

Also changing the Coil pack ( 260 Dollars from US for V6 ) was the remaining option but at present I am happy with the running considering the car's mileage.

Just a thought.

Mark.

[brd]

Ah... interesting.
I got a secondhand Mass Air Flow meter and just stuck that in... so am driving it now to see if its ok. So... I'll keep you posted if it works as yes, it is damn annoying!
Interestingly the guy in the garage asked me the same thing for the cam belt, ie when it was changed. But I don't understand how that could give intermittant problems though.

Anyway... fingers crossed that its fixed! If not, then next stage is a new Engine Coolant Temperature sender.... but thats alot less painful than a MAF (200 euro secondhand).
B.