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High Idle Problem

tom_v

By tom_v,
in Engines & Forced Induction

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tom_v Rising Star

tom_v

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I have a r33 rb25det. I recently blew the turbo and replaced it with a high flowed and rebuilt rb25det turbo. Now the car is idling between 1200-1500rpm at all times. it Doesnt change whether its cold or hot and i have checked all vacuum lines, every gasket on the intake side of the engine, basically everything. I have since put my stock BOV back on and besides the front mount intercooler kit, pod filter and exhaust the car is stock.

As for boost control i am using just a vacuum line from the intake manifold to the turbo actuator.

Ive run out of ideas as to what it may be so any help would be greatly appreciated.

Thank you :P

Edited by tom_v
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https://www.sau.com.au/forums/topic/316232-high-idle-problem/
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tom_v Rising Star

tom_v

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Just found the DIY for "Aac Valve Cleaning & Idle Reset"

http://www.skylinesaustralia.com/forums/Di...nd-t110431.html

Ill give this a try and see how i go, i really wish it didnt get dark so early now, bring back day light savings! lol

tom_v Rising Star

tom_v

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I just finished cleaning out the AAC valve. I Disconnected the TPS and let the car idle. It sat at about 1200rpm as it previously was. i then turned the adjusting screw on the AAC valve to lower the idle. i got to about 950rpm when the screw was fully in. Im guessing it is still not right cause it should not be all the way in. Should i adjust it now on the ecu??

Also there are two plugs on the TPS, i did the adjustment with the grey top plug disconnected as when i disconnected the redy/brown plug it just reved very high. Was this correct???

Edited by tom_v
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Ill check that its bled properly, it probably isnt, but would that really make it idle all the time at 1200rpm? Like even when its cold and first starts up?

the idle control valve has water running through it, air lock will cause it to do weird things.... S15's are the worst for it as the water runs through the TB... they will idle around 2500rpm if airlocked :D

tom_v Rising Star

tom_v

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Ive checked the cooling system, its all bled up fine. Im wondering if because its a high flowed turbo it may be pumping in more air then a standard and rasing the idle. Has anyone put a high flow on and experienced something like this?

tom_v Rising Star

tom_v

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Ive adjusted the idle by clamping off the pipe to the AAC valve and setting the base idle by adjusting the little screw on the throttle. I did this with the TPS disconnected then after setting it all, reconnected the TPS and switched the car on and off. It now idles at 900rpm nicely and the AAC valve adjusting screw is not all the way in... Is this ok? Ive listened and checked all vacuum lines, even checked by spraying brake cleaner over every line and did not get any reaction from the engines.

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