I have an interimittent fault on my Audi. It's the 94-97 model (P reg).

Most of the time it runs fine, but I have an idle problem in that I start it up and it runs at high idle (approx 1500rpm). Then after a while it starts revving up and down between 1200-2000rpm. I've noticed that when the double radiator fans kick in the engine stops revving up and down but still remains at a high idle of around 1500 rpm.

Worst case I had was that I turned it on and it went straight up to 3000rpm! And then started revving between 1500 and 3000 rpm.

I can still drive the car but it's no fun as when I am moving and take my foot off the accelerator the car jerks badly.

I've got a feeling it's the idle control unit/valve or some sort of electronic fault but without diagnostic software I can't check the latter without taking it to a main dealer which I am loathe to do as they are so ****ing expensive.

As mentioned above, it doesn't always happen. It started happening again last night after not doing it for nearly 2 weeks, and there seems to be no obvious reason for what triggers it.

Anyone else had this problem and solved it?

Anyone know where I can get the diag. software cheap or even for free? I've heard that VAG-COM is what I need but again, I am loathe to pay out for that as I am on a tight budget (out of work )


Any decent suggestions would be very much appreciated.

cheers

 

your local auto parts store will read the codes for you for free, you are on the right track with idle control check your connections for corrosion or a short.

 

OK, long time since I posted regarding this fault and it was solved about a week after I posted my questions.

It turned out the problem was my battery. It had a dead cell so when the engine was starting it was occasionally getting an incorrect voltage which was sending the idle haywire. New battery fitted and problem was solved.