Audi 80 2.0L ABK engine juddering/misfire

Hi Stridey..

Can you give more details there about the immobiliser system? Mine is in the garage at the moment ... still trying to find it and could really do with any pointers.
Thanks! B.

what part of engine immoboliser did you fix and what did you do to it, did you totally replace it? and where the hell is it, my wife is driving me crazy she wants it working yesterday!

I just joined the forum to further understand the very annoying ABK engine issue. Hence a very shameless bump :D

I have a 1996 2.0E Avant with around 111k on the clock.

My car usually plays up when the engine is cold - after it's heated up it's normally fine. The last time it happened, I pulled over and sat with the revs at 3k. It coughed and spluttered and dropped to a very lumpy 1 -1.5k, and then jumper back up to 3k. This happened a few times, and then I drove off - not to happen that evening again, nor the the next morning.

Last year, I drove from Edinburgh to Glasgow, up the side of Loch Lomond to Fort William, over to Inverness and back to Edinburgh in one very wet evening without the car skipping a beat. And other times it happens every time I drive the darn thing.

I usually drive my van, and keep the car for outdoor pursuits, so I don't do high miles in it.
I would like to keep the car so much as I love the styling, and have played with the idea of dropping a 2.9 lump into it. But I'd be as well just buying a Corrado if this issue fails to get resolved......

I've had the issue for several months, seems to have got worse too.
Recently the car totally died while I was driving along, tried replacing distributor but didn't seem to fix it, did the coil and HT leads too, still didn't run (no spark or single spark). Then charged up the battery (it was still cranking not dead at this point just no spark) and after a charge she started back up. (guess voltage got too low to run computer) Reset the timing and initially seemed smoother.

Now the juddering is back again. DOH.

The ignition system in the ABK is the Bosch Digifant. Try googling for "digifant", there are some useful guides out there. I also discovered the ABK engine is not covered by the Audi 80 manual, but if you get the Audi 100 and A6 combined manual (mine has green cover) the ABK maintainance information is in there.

If you want to read the fault codes from your car get a VAG-COM lead from eBay and a 2x2 adaptor for £20ish. There are two connector a black and grey each with 2 pins in the fuse box in the tray under the wipers. On mine the connectors are in the corner of the fusebox nearest the wing. You'll see them if you lift the lid as you would to change fuses.

I read my fault codes with shareware version of vag-com and got the following
engine temp sensor
lambda sensor
throttle potentiometer

The engine temp sensor we disconnected while doing the timing.
the lambda sensor I replaced and tested running the engine with it disconnected.
The throttle potentiometer I'm not so sure about.

Does anyone know what the resistance should be closed to fully open?
Mine I think was about 2-6K (from memory so probably wrong) There is a 3 pin connector on the potentiometer. anyone willing to measure theirs to compare?

Also I read about performing a 'basic setting' on the ECU. Could somebody explain what that is?

This lumpy running is now happening hot and cold.
It's now happening every time the car is driven. Last week, it happened 40 miles into a 50 mile drive.
That same evening, it happened 2 minutes when I decided to drive into my very busy main street. I had no choice but to pull over and cause a massive traffic jam on my side of the road:aargh4:

Last night, it happened 50 yards from my house. So, after waiting at the side of the road for 10 minutes (yes 10 minutes) for the engine to calm down, I popped into the garage and booked it in to get the timing checked. It's going in on Tuesday, so if it improves I'll report back.
I had the belt done just after I bought the car, so perhaps things have moved a fraction since then......?

The annoying thing is that I have somebody wanting to buy the car, but there is no way that I'm going to sell a car on that's running like a it's on 2 cylinders :zx11:

I think my car might be cured!! :biglaugh: touch wood.

It's something so simple, it took about 30mins total to do.
I've only been for a fairly small run so far - tomorrow I'll be doing my commute so I'll know almost for sure then - will let you all know. (confidence grows with time, don't want to get too carried away yet)

Under the steering wheel is a facia panel which can be removed it's about 4 8mm bolts, (this facia covers the entire area under the steering wheel between the center console and the edge of the dash.)

Remove the fascia panel and there is an area in which relays may be present. (Relays are small usually black or grey cube shaped.)

On my audi 80 2.0E 93 ABK I could spot two relays, one really long one and a smaller squarer one tucked slightly higher up. I think the long one had a 3 digit number like 203 written on it and the smaller on has 30 written on it.

I removed both, I couldn't get the long one apart easily and didn't want to force anything, but the smaller one came apart fairly easy once removed from the car. Inside the relay casing there is a small pcb. (circuit board). On this board in the top corner I spotted a dry joint!!

I got out the soldering iron and resoldered the joint. the other joints looked ok so I pretty much left them as they were and clipped the case back onto the relay.

Having refitted the relays I've been for a test drive and I hope it's not placebo effect of my excitement of maybe curing the car after being frustrated with it for so long, but it 'seemed' to run much better than before and no hesitation/ juddering over the few miles I did.

I think anyone who has problems with their ABK audi should check this relay. It can easily be checked in about 15 minutes.

Before I did this I have spent money on 2 manuals, a diagnostic lead (which did not show any faults) distributor, fuel filter, ht leads, coil and coil pack!

I think the theory is that the dry joint causes a drop in voltage which causes problems with the computer (ECU) Interesting though my diagnostic lead showed no faults.

I found a site with some images of relays with dry joints. Should give you a clue as to what to look for.
http://www.marklamond.co.uk/tech-hon...main-relay.htm

It is definately fixed!! who would have though 1 dry joint would have caused so much grief.!! now the engine is running much cooler and the bonnet no longer gets hot enough to fry eggs and evaporate the rain!! lol :beerchug:

If someone else tries this and gets success please post here about it - I'm interested to know if anyone else's digifant ABK Audi 80 runs like a dog because of a single dry jont on the ECU relay!!!

YIPPIE!!!

The Audi 80 is a great car to own again, I was ready to ditch it before....

Fantastic fella, i'm well pleased for you, its been like reading a long book going all the way through this thread, at least i know the solution if my ABK goes silly.:beerchug:

Hi Millerman, I can't believe something that was so easy to fix has been causing me grief for maybe last 6 months.!!

Regarding the PM question about the manual, the Audi A6/100 Haynes manual covers the ABK engine which was fitted to VW golf (I read early GTI - unconfirmed), Audi 80 and Audi 100/A6.

To cover Audi 80 and ABK engine you need two manuals, one for the car and one for the engine.

I bought my Audi 80 manual (red cover) on eBay. The Audi 100/A6 manual was bought in my local halfords.

After all that, the actual solution was not found in the manual. I stumbled upon another forum via google where somebody had a similar issue.

Good luck all, please report your success - I'd like to know if I've helped somebody cure their headache...

Steve

Cheers Steve, it would be good to know the function of that particular relay, ie; what does it protect?