VR6 Idle issue

[mpgscott]

Ok,

A couple of weeks back i had an issue where i started the car from cold and it would not run unless i had my foot on the throttle, it just would not idle the revs just fell off.  Now after i took the car for a run it cleared and started to run fine.  Now for two weeks there have been no issues turn the key without touching the throttle and it runs fine.

Today it did the same where you needed to give some throttle so it would idle, difference being that this time it has not gone away, even when warm the car is only idleing at around say 500rpm and when cold it just stalls if you dip the clutch and let it freewheel.

Anyone got any ideas as to what could be the problem?  Do the VR6's have idle stabilzation valves?

Other than this the car is fine it is not loosing power and it feels fine just wont idle.

Cheers
Mark

[AudiA8Quattro]

OBDI vr6 has an idle stabilisation valve, OBDII does not, it is ecu controlled only.
I think the change over year is about 1995.
I would also check the switch on the throttle body.

[VRDan]

I no and have experienced problems with idle on later vw engines. If the fault was with a sensor it is most likely the ECU would flag up a code and bring on your management light.
If you remove the air intake pipe leading to the throttle body and look inside at the butterfly you may see black carbon e.t.c around the face.
In the past i have removed and simpley washed the throttle body out with brake cleaner and after Re-fitting have found this to have stablised the idle speed.
Might be worth a shot as a cheap quick test. 

hope this may of helped.

[mpgscott]

Cheers for the responses.

Well i hooked up the laptop and vag com showed three fault codes.



So i had a look and there was reference an issue with power so i removed the negative terminal to the battery for 5 mins and then hooked back up and now the car is running fine.  Also there are now no faults on vag com very strange.

I did notice this morning that it looked like the battery had been flat as my trip on the dash was reset and also the computer on number 2 switch did not show any info which was odd.  You know for amount of hours run, so it looked like the battery was an issue.  Odd enough thought the stereo still had all its settings such as radio channels and audion settings, and if you remove the battery for a split second the stereo looses the settings.  So not sure what has happened to cause the dash to look like the battery was removed very odd..

Any thoughts?

[AudiA8Quattro]

You have got a shareware version which isn't telling you what the codes mean.
Check your fault codes here:-

http://wiki.ross-tech.com/index.php?title=Category:Fault_Codes&until=01794