Revs fluctuating (G60)

[DANG60 0]

My car idles fine until its warmed through and then once its up to temp at idle the revs fluctuate between 1000 and 1500 rpm. Its athough its revving itself up.

If I was to turn the ignition off and then start the car back up it will idle fine until I physiaclly drive the car. My guesses are isv needs cleaning or some sort of vac leak well something along the lines of that. I was just wondering has anybody encountered this themselves and could maybe hit the nail on the head as to what it is. P.S the car drives fine under load if anything a bit jerky between on/off throttle transistions.

Any help would be great as I look like an idiot at traffic lights because I have a bbm screw charger on lol :lol:

Thanks everyone.

[Album56 0]

Had something similar on my standard 92 G60, revs would hunt from 500 to 1500 when warm, in my case turned out to be faulty blue temp sensor which had gone open circuit which meant mixture was rich but the isv was trying to compensate hence the hunting. Available at dealer only a few pounds, get new sealing ring & very easy to replace. Do it with cold engine & keep cap on expansion tank & you shouldnt loose any coolant.

If you have a multimeter on ohms range you can check it , starts at something like 3k ohms with cold engine & drops to approx 200 ohms or less when hot.

Mick

[Traverse 0]

Mine did this when my ISV was bad... I'd start there.

[flusted 0]

yeah id start at isv clean, although mine does this and i have new vag bts and no isv :cuckoo:

[DANG60 0]

Excellent, cheers guys. I will try this out.

[CazzaVR 0]

Check out the ISV pipework thoroughly, for small splits.

[DANG60 0]

well i finally got round to checking out the problem. At the back of the throttle body there are about 3 ports. One of them is blanked off the other one has the 1m line to the ecu. There is another one above this, the car is drawing air from there. If I block the hole with my finger the car idles fine again. Does anbody Know whats supposed to be in this hole? Am I ok just to run it blanked off or is there usually a screw or something that lives here? :shrug:

[Supercharged 2]

Idle screw dude!!

 

You will need to get a new one from VAG - about 50p

[DANG60 0]

wicked... thanks for that.