Idle Stabilisation Valve problem

[james97]

Hi to all I have a 1997 Automatic A4 1.8 and all of a sudden it seems to have developed a fault of not idling however it seems to run well if I keep reving it.

I have read some problem tech pages that leads me to believe that it could be the IdleStabilisationValve does anyone know where this little sucker is located in the engine bay. Photo's would be appreciated.

Regards james

[a8 tech]

Hello James,your engine type uses a throttle body and it is not uncommon for the recirculated engine gases to build up a carbon lip inside the throttle body causing the flap to bounce and cut off the small air gap required for idle.I advise you to remove the litle bugger and giv it a clean out worthy of a hospital surgery and refit and readapt the learnt value/basic setting via vag com and takr it from there.Also pay attention tothe breather pipes as they crack with age and cause unmetered air leaks which also can have the same symptom.Regards A8

[james97]

Hi, A8 , thanks for getting back to me so fast... excuse my ignorance when you say throttle body type I am assuming that you mean take apart and clean the part that the accelerator cable connects to, I am assuming there will be a large butterfly inside here. Are you saying my car does not have an idle stabalisation value. Regards James

[a8 tech]

Yes James,the throttle body controls the idle settings and feeds back to the ecu when its at rest and when you press the gas pedal.

[a8 tech]

150174577579_1.jpgIt should look something like this

[james97]

Thanks will give it a go tomorrow so i am not looking for a ISV to cleen.

James

[james97]

Hi a8
Well did all that removed the throttle body gave it a good clean did not seem that dirty to me but got a thurer flush through with carb cleaner. check for leeks in all the associated pip put it all back to gather and it seen to be wers now when I hold the revs at 1500 they seem to serge between 1500 1900…leading me to think it cooed be the ECU..

Regards James

[a8 tech]

Hello james,you need to readapt the settings which will mean you either buying vag com or sk your local dealer to adapt the throttle body for you and this should resolve/eliminate the problem.

[james97]

Well got my local garage to plug they thingy in and it all seems to be ok now. I notes that there all so have replaced the jubilee clip at the mouth of the throttle body. I was thinking about what you said about buying vag com. I was looking at some cabals on ebay wot would you suggest. James

[a8 tech]

All fixed then,if you buy your diagnostic lead from flea bay you will require a software license VAG-COM Software License: Ross-Tech Store so you can use more fuctions of vagcom