Icv ?

[daddy5times]

hi ive just replaced my i c v on audi coupe ace engine cos idle was up & down ive replaced with 1 that has same part number but problem persists any ideas lads/lasses:p :zx11:

[kenney]

Have you had a fault code read?

[daddy5times]

no mate i havent my neighbour said if i leave battery off over night any f codes would be removed and that might be problem ecu thinking icv is still faulty could this be right

[kenney]

The fault memory is designed as a non-volatile memory. It is however dependent on the power supply. Disconnecting the permanent positive supply erases the fault memory of the engine control unit.

[daddy5times]

ive just checked all air hoses for holes and ware but all seem ok also sprayed wd40 on inlet manifold gasket area and no change :zx11:

[Eshrules]

no mate i havent my neighbour said if i leave battery off over night any f codes would be removed and that might be problem ecu thinking icv is still faulty could this be right

tip number 1 - stop listening to your neighbour, he's wrong and issuing poor advice.

fault codes are logged, to be read, not cleared ignorantly I'm afraid.

tip number 2 - get to a garage, or to someone who has fault scanning facilities and read the codes.

report back here the codes you've got and people can offer more specific advice

[NickPicks]

tip number 3 - post in the Audi Coupe section instead of the new user introductions section that a lot of people don't read.

I also agree with tips 1 & 2

[audi80mk4]

Did you sort it ? If not, try http://forums.pelicanparts.com/porsche-911-technical-forum/346667-motronic-idle-surge-solution.html

We have the same problem and found this by searching on 'audi idling' or similar IIRC.

[scotty33]

hi ive just replaced my i c v on audi coupe ace engine cos idle was up & down ive replaced with 1 that has same part number but problem persists any ideas lads/lasses:p :zx11:

Try cleaning the gunge build up from inside the throttle body. The hardest bit to do is in the area where the throttle butterflies are, this is unfortunately the bit that needs cleaning.
Idle jumping around is often a sign of the ISV operating fine but struggling with low airflow through the 'normal' route.

[audi80mk4]

Offered without guarantee or liability : we cured the idle speed variations on our Coupe (3A engine with Motronic) by doing what our Golf 4 handbook said ! :D Can't say if it was a permanent cure because the car has been sold.

Turn the ignition on for 30 seconds but don't touch the throttle or start the car. Turn the ignition off again, then start the car, still without touching the throttle.

In our case the fault code (have it/them read first) pointed to the idle stab. valve, which we had replaced, so I removed the 'Motor Moteur' fuses for several minutes to clear it before doing the above.

My impression is that these procedures also force the ECU to reload its original look-up tables from EPROM or wherever it keeps them.

Any comments welcome, of course. HTH.