Audi 80 2.0L ABK engine juddering/misfire

**niall4313** · 13-01-2009,08:04 PM

Ive tried all of these suggestions plus a good few from other forums and still no luck almost a year later!!

**Jillbaby** · 04-03-2009,08:35 PM

Quick update from my last post - still no recurrence of the juddering problem so it looks as if resoldering the joints was the right thing to do. However, I have had some starting problems recently (taking a while to cough into life when turning over) which eventually led to the car refusing to start at all after a couple of very short trips. AA got it going to get me home but it's now in the garage and they are going to try a new temp sensor as it appears too much fuel was being injected and flooding the engine. It starts fine from cold and when the engine is warmed up but if I stop before the temp gauge needle moves up it doesn't want to start again. If this doesn't work they are looking at putting in a new fuel metering something or other (come on, I am only a girl after all

). It has certainly been running very rich again lately, although not as bad as it was before fixing the relay, so maybe this will solve this as well. Will let you know what happens

**Millerman** · 05-03-2009,06:34 AM

Fingers crossed for ya Jill.

**Wings** · 07-03-2009,01:02 PM

Hiya Jillbaby.
My Audi 80 -'94 does not have a relay no. 30 therefore I have been struggling with this jitter-thing...however, I have found the solution and it might help you as well.
On the waterhose leading from the engine to the radiator (on top of the engine) you will find two sensors, one white (3-pol) and one blue (2-pol).
The white is the "feeder" to your temp-instrument on the dash, and the blue is the "feeder" to the brain. The blue will tell the brain at what temperature your engine is at, thereby feeding info to the brain and the brain is distr. gas accordingly.
My blue sensor has a resistance of 2,8mohm cold, but very quickly it drops to less than 1,5mohm. In speed I'm talkin 'bout app. 3 minutes. After this the engine thinks it's warm and shutting of ISC (idle speed controller).
Also this will result in running too lean whereas it should have run rich, causing the engine to heat up to max often, and the rad-fan will kick in too often.

Hope this helps.

**niall4313** · 15-03-2009,05:06 PM

Hi ive posted here already without much response I was hoping someone might be able to help me with this problem I have an audi coupe 1995 2.0, abk engine .the problem is that it will start at the first turn of the key and run perfectly but after about 10 minutes or so it starts to shudder and splutter eventually getting worse until it cuts out. So far i have replaced the distributor, leads, coil, vaccuum hoses, ecu, ecu power relay no 30, all to no avail. i ran a diagnostic on it today and got the following codes:

00513 engine speed sensor g28

00522 engine coolant temp sensor g62 27-00 implausible signal.

the car is in mint condition and this problem is doing my head in, can anyone shed some light on what the codes mean, ive already replaced the temp sensor so im lost here!

thanks in advance

**scotty33** · 17-03-2009,12:18 AM

Hi,

Sounds like a nightmare!
I think the G62 temp sender is the one for the ECU, this is the blue one on the plastic water pipe on the side of the head. If you changed this one already, you may have a wiring fault, or extremely bad luck and it's gone bad again?
I think the speed sensor code may be a red herring, sometimes this code comes up if cars are scanned when not running. If it was bad I don't think the car would start, though the symptoms do match a component breaking down as it warms up, equally, it could be a bad temp sender failing to shut off the cold enrichment even though the engine is warmed up?
Try scanning it again when running?

**niall4313** · 17-03-2009,12:05 PM

Hey thanks scotty, Well I have changed the temp sensor and I kinda was thinking it may be faulty so first chance I get Ill order one.. well two actuallly cos it gets worse, I bought a 100 recently for a runaround and its developed a similar problem, same engine code problem isnt as bad as the car is driveable just idling badly. I have a thread here about it in the 100 section and was advised to try the temp sensor also.
Just one other thing could it be the throttle potentiometer on the throttle body? Ive take the whole thing off and cleaned it out changed the isv as well, made little difference though. Its been well over a year now and if it takes me 10 more years im not going to give in!

**Wings** · 17-03-2009,12:24 PM

My first guess would also be the blue sensor (as described in my last reply) but could it be false air from a crack in the TBI-manifold? (the rubber-thingy underneath the TBI)

**orion248** · 31-03-2009,10:57 AM

Cheers Steve

Had a problem with intermittent rough running for months on my 1994 Audi 80 2.0E Auto.

Couldn't solve the problem by changing plugs, HT leads, dist cap etc. Read your post, purchased a new ECU relay from an independant VW/Audi parts supplier at about £7 and has run without a problem ever since.

Thanks again for posting this info, saved me from parting with a mechanically sound car that couldn't pass the MOT emissions test.

A diagnostics test had shown that the voltages to the ECU were "all over the place" so presumably the injection system was receiving rubbish signals, lucky the car was running at all. Does this unit act as a voltage regulator?