C34 Rs4S Idle Speed

[c34Florry]

With a search wielding no definitive answer, a new topic it is...

All my other manual cars over the years have idled around 650. All of these cars have been na btw. Even the charger (auto) in park idles at 800..

My s2 stagea rs4s idles when warm at 850-900 rpm. Is this normal or is it too high? (Under the bonnet on the leading edge there's a sticker that says 650) so theres conflicting info already.. is it something to do with turbo and needing to idle higher maybe? How do I adjust it.. if I need to?

Edited March 7, 2014 by staglover

[zoomzoom]

900 sounds too high. Have you tried cleaning the AAC valve? That in itself wont set the idle but there is a screw on there which may be letting in too much air at idle. That screw can be adjusted to bring down the revs. Cant remember the exact idle speed off the top of my head, but I believe the auto idle is slightly higher. 700-750 is what mine is around.

[wolverine]

Are you running the factory ecu or aftermarket?

If stock ecu adjust idle screw to desired rpm and see how the car likes it.

650rpm is not that happy on both my RB's so I always set it a little higher.

[zoomzoom]

From memory, logging the timing using a consult cable is also a way of seeing if the ecu is trying to regulate too much air entering the engine at idle. If you see the timing fluctuating that may be a problem. Ill have to dig out my old ecu logs.

[c34Florry]

Thanks for the replys guys. Stock ecu as far as I know.. ive had the car 3 weeks or so from japan and its been at 900rpm since. Runs nice but I always thought it had been a little high.. please excuse my ignorance but what is an AAC valve and where is it located? I thought about adjusting the idle control screw but wasn't sure if that would throw out anything else.. bah ecu's lol

Edited March 7, 2014 by staglover

[Ben C34]

Don't adjust the throttle stop (which I think you think is the idle control screw)

There's plenty of info around on how to clean and adjust the aac.

[KiwiRS4T]

Thanks for the replys guys. Stock ecu as far as I know.. ive had the car 3 weeks or so from japan and its been at 900rpm since. Runs nice but I always thought it had been a little high.. please excuse my ignorance but what is an AAC valve and where is it located? I thought about adjusting the idle control screw but wasn't sure if that would throw out anything else.. bah ecu's lol

http://www.skylinesaustralia.com/forums/topic/110431-diy-aac-valve-cleaning-idle-reset/

[c34Florry]

moi bien! Gracias senor