vr6 high idle after plug and ISV clean

[edd 0]

Ok so having had a bout of early morning crappy idle and associated stalling, i decided the vr was due some new plugs and an ISV clean

 

Having undertaken said works i now have a car that runs lovely with the foot on the pedal and has a fairy smooth idle (most of the time). .......

 

However

 

idle will not drop below 1000rpm (it is definitely higher than it was, i know this car having had it for 7 years).

 

Have checked obvious possibilities such as air intake pipes etc no leaks evident anywhere. All clips well tightened

 

I have swapped the MAF recently (1 week before this work) from another VR i have just to see if it made any difference to the stalling issue i was having before (it didn't resolve, but also didnt effect idle). Both cars are 1992/3 and stall upon MAF disconnection.

 

I have also tried adjusting throttle valve sensor in case garage had adjusted to compensated for a dirty ISV in some way but could only get this to facilitate an increase in idle

 

i did replace blue temp within the last 6 months but was a GSF one....bit coincidental if that was suddenly the cause though

 

Any further thoughs - it was definitely straight after ISV and spark plug change that it started happening.

 

doesnt appear to idle high on start then drop off either just always 1000rpm.

 

Help, its annnnnoooyyinnngg me.

 

Sorry for any bad typos. its late, im annoyed., im tired...

 

Edd

[RW1 0]

Look for an air leak where you have been working or the ISV is stuck partly open.

 

.

[edd 0]

had a good look/feel around but cant see or hear any form of leak, have swapped over ISV's over from the other vr6 (which idles perfectly with both ISV's).

 

Made no difference to this one....

[floppyman 0]

Maybe the trothle body is a little bit open..... Check the dashpot, might not be letting the tb close

[Yandards 0]

Look for an air leak where you have been working or the ISV is stuck partly open.

 

.

 

I was thinking that the clean ISV and new MAF would be more efficient than the old original items and the ECU might still be using the older adapted values for idle control?

 

If that is the case it should sort itself out after some driving but you can speed the process up by doing an ECU reset by removing the battery lead and following the guide here

[davidwort 0]

did you clean the ISV with petrol? It might benefit from a light 'lube' with WD40 or something.

[Kevin Bacon 5]

I have also tried adjusting throttle valve sensor in case garage had adjusted to compensated for a dirty ISV in some way but could only get this to facilitate an increase in idle

 

How did you do this exactly? By turning the throttle stop screw? If you have done this you will need to plug it into VAG-COM and make sure the TPS at rest is 14 degrees or less. If it's higher than this, the idle valve won't switch on as the ECU thinks you are driving.

 

I doubt the ISV is stuck open. I've never seen one jam solid through normal use. They are partially open anyway by default and have a very strong return spring.

[edd 0]

car started 'hesitating' down the motorway on the way home from work, had to be air leak, got home took all the breather hoses off, reinspected and found a split had opened up in the cylinder head breather. installed new breather hose

 

disconnected the battery for a while to clear any faults etc and restarted sat nice and smoothly at 750rpm.

 

thanks for the advice all.

 

Better get someone to VAG.com me now see if ive messed anything else up.......:)