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Gday guys,

I got an rb20det in an r32 that is giving me a problem.

At idle it is surging between stall before it rises to normal idle at 700 and does this continually and sometimes stalls, this has became ever increasingly annoying in town driving as it stalls when you put the clutch in and while its in nuetral.

If we disconnect a vaccumn line and let it suck straight air it returns to a normalish-high idling range but with no surging.

ECU shows of no error codes.

Driving me insane, anyone got any ideas?

Regards

Stan

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Hi dude,

We had that problem too. The problem is a faulty Idle Air Control valve (I think that's what it is called). Ours was stuck half closed or something.

Clean it, and try again. If that fails the solenoid inside will be broken and you'll need a replacement like us.

wil..

Really? damn thats a tight spot to get too :teehee: will have a crack at it and see if we can clear the problem.

Thanks heaps mate, your a champ.

Stan

Its the Auxilliary Air Control valve (AAC) that you want - hangs off the back of the plenum.

It's been the cause of thousands of threads.

yeah and 9 times out of 10 its the IAC valve thats down near the fuel rail thats the cause of the prob. i had the exact same prob, followed by a consistant high idle, so i cleaned the AAC valve which did SFA, so i just blocked off the IAC valve and now it idles at a smooth 900 rpm, cause i couldnt be bothered fixing the damn thing thats so hard to get to

IAC gives a constant high idle speed, the AAC valve gives a "hunting" idle speed.

tazr32 has "hunting", so it's more likely a problem of a dirty AAC valve.

(On a 32, the IAC valve is the one underneath the throttle body. On a 33, it is under the inlet plenum. The AAC valve hangs off the back of the inlet plenum on both models)

I think I might have a dirty AAC valve because my car wont idle. It drives fine but when you come to a stop it idles for a second before dropping out and stalling. When I restart it idles fine, but once I start driving again the first time I stop the idle just drops and conks out again. Does this sound like a dirty aac valve problem? To clean the aac valve do you use carby cleaner?

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