My car is still idling at 2000~2500 rpm's according to the rev counter - I have no real reason to doubt that it is reasonably accurate, the revs sound high too. Adjusting the TPS makes no difference at all, it fluctuates for a sec but then resumes the same rpm. The TPS no longer has the weatherproof connector, but someone has crimped connectors onto the wires which then plug into the sensor. Do these often go faulty?

 

The A/C switch is off, and it just adds an even higher rpm!

 

Any thoughts? I've read there is a more crude method of adjustment somewhere...this has possibly been set by a previous owner for some reason and may be worth looking at if I know where.

look at the idle control valve. its near the battery mounted on the back of the plenum. if you pull the plugs off so the ecu can't control it and wind the screw in until it settles at around 750 iirc. then plug the connectors back on and see if its ok.

Hope this helps

Thanks Damo, I will try tomorrow.

 

I've also noticed the mixture smells very rich out of the exhaust, so could be over-fuelling?

 

It has also been de-catted, what happens with the sensors (lambda etc) when these are removed?

I think v6's tend to smell a bit rich anyway mate, well my Z and vectra both do anyway.

The de-cat shouldn't affect the lambda as they are on the downpipe off the turbos and are before the cats anyway

look at the idle control valve. its near the battery mounted on the back of the plenum. if you pull the plugs off so the ecu can't control it and wind the screw in until it settles at around 750 iirc. then plug the connectors back on and see if its ok.

Hope this helps

 

I think I've located the screw, I can't see clearly enough as to which cable needs unplugging (it's very busy down the back). I've unplugged what I thought might be the ICV but still cannot get the revs to lower :(

did u adjust the screw all the way? another thing that might be worth looking at is the "cold start" thing (can't remember the name exactly) it sit in the middle at the back of the plenum.

I had loads of issues with high idle and couldn't get it to settle down. I cleaned all the air control valves, but that didn't work. In the end my frustration got to me so i started tapping them and when i hit the cold start it dropped down to a proper idle

Worth checking it though