R32 Gtr High Idle 1100rpm?

[nonickname]

Hi guys, before i go checking every hose etc on the car. i was wondering if anyone has had this problem and knows off the top if their head how to fix it?

1990 r32 gtr, standard ecu. this car has for some reason decided to idle at 1100rpm for a few weeks now. stil runs smooth and nothing has been touched in the engine bay. it also feels a bit underpowered to me. any ideas?

[skybox 32]

dude wrong thread.. but i would clean out your afm... does it do it on start up? or idle at the lights? when the car is cold or normal op temp? It could be a lot of different things

[Amec]

its amazing how many posts can be answered with "boost leak"

[nonickname]

yeah sorry bout posting in the wrong place. but anyways it idles like this all the time. id agree with the last reply...time to find the leak...oh yay

[DS-ZILR]

i know that my manual that i had but lost said that normal idle is 950rpm ish and that i have a nice split turbo outlet pipe and leaks like a mofo so i am at 1100 rpm at my idle now. so yeah just confirming to have a look for that leak.

good luck. good trick try real soapy water arround hose clamps and joins and see if it bubbles.

enjoy

[nonickname]

Cheers guys. im gonna chuck a boost gauge on tomorrow n hopefully that tells a tale. i had a similar thing happen on a mitsi gto that turned out to be a leaking hose under the inlet manifold on the old twin turbo v6. i imagine its the same deal here. Are there any hoses other than turbo outlet that are known more than others to leak?

[Bart Japan]

I too have been trying to fight the evil high idle. I have at least stopped it hunting by looking at the guides for cleaning the AAC valve and have recently diagnosed that my idel switch in the TPS doesnt work (I think that anyway). I am sure that I am getting air in maybe near the inlet manifold so Ray at RE Customs said try spraying brake cleaner around. If teh engine changes pitch then the brake cleaner is being taken in and burnt. I am not sure if this will work around the rest of the pressurised system.

Anyway keep us posted on any eventualities

[AllenSaldi]

I wouldn't use brake cleaner .... I would use carburetor cleaner or starting fluid. Brake cleaner isn't something you want your engine ingesting.

[gtr fan]

My car used to allways idle around 1200 and now just hunts for idle all the time. engine temp doesn't make difference.

Think I will do the AAC valve first as people seem to have good results. How do I check the Idle switch on the TPS?

Thanks for any assistance.

[jantolis]

My car idles at 1600rpm and no obvious boost leaks either. Been like that for a very long time. I don't think i'll get it sorted until i do a rebuild and go over absolutely everything. Car still runs fine and has no other issue.

[den001]

the 6 throttles that bolt to the head have like a clear coating around them internally where the butterfly's close, if any type of cleaning agent is used inside, say like a system cleaner or carby cleaner, it can eat away at the coating causing the butterfly's never to seal properly again, never spray anything in there...

make sure the idle screw is screwed in, if its all the way in and it idles high, ^^^ is your problem... not fixable on the cheap side and its a off job to do so..

[nonickname]

hello again. i put a boost gauge on the car today and it is running between 11-14psi. seems like 12psi most of the time, the car usually runs just over and holds 14psi when it was running correctly. now i've checked hoses etc and all seem to be ok. the two running off the boost solenoid look at bit old but they have always and never caused a problem in the past.

BUT...on further investigation i have found that the injectors on 4th and 5th cylinder appear to be leaking from where they connect to the fuel rail. is this what is causing my high idle possibly?

the car is going on the dyno at created performance next week to see what the hell is goin on with high idle and slight lack of power, but i would like to figure it out before i take it there.....not to avoid cost of checking/repairing, more so i can see what shes really got at the wheels knowing that its running correctly!

THANKS FOR YOUR HELP SO FAR GUYS!

[GeeTR]

I wouldn't use brake cleaner .... I would use carburetor cleaner or starting fluid. Brake cleaner isn't something you want your engine ingesting.

Why not?

[GTScotT]

tried adjusting it, i know it sounds stupid, yet theres a way to do that properly to, and even use a consult to goto the set idle mode

[GeeTR]

^^ Theres a grub scew on the idle control solenoid... but u should prolly try and find the cause.

[LotusGTR]

the 6 throttles that bolt to the head have like a clear coating around them internally where the butterfly's close, if any type of cleaning agent is used inside, say like a system cleaner or carby cleaner, it can eat away at the coating causing the butterfly's never to seal properly again, never spray anything in there...

make sure the idle screw is screwed in, if its all the way in and it idles high, ^^^ is your problem... not fixable on the cheap side and its a off job to do so..

Yup, I got told this too by my mechanic. He was able to adjust the idle down with the Power FC. Still about 1000 at idle. Said it's a real fiddle to fix.

[bigmikespec]

I had the same problem with high idle, about 1100rpm. I thought it was normal until I looked on the inside of the bonnet one day and I think it said idle should be 950rpm or there abouts.

I got my Vipec V88 installed and my tuner spent a lot of time getting the idle right (as his dyno was getting fixed he had about 3-4 days to do it). Now is sits on about 700rpm and seriously it sounds sweet and never skips a beat.

High idle was with the standard computer by the way.

Mike

[jantolis]

the 6 throttles that bolt to the head have like a clear coating around them internally where the butterfly's close, if any type of cleaning agent is used inside, say like a system cleaner or carby cleaner, it can eat away at the coating causing the butterfly's never to seal properly again, never spray anything in there...

make sure the idle screw is screwed in, if its all the way in and it idles high, ^^^ is your problem... not fixable on the cheap side and its a off job to do so..

ahhh nobody has mentioned that to me ever but it makes perfect sense. That could definatley be the culprit. Oh well i'm not really to fussed about it for now as long as it won't damage anything. I'll wait for a rebuild or new motor me thinks before i do anything about it.

How hard is it to take the plenum off to fix this though. Could i do it in a day??? just incase i get bored one weekend. car is off the road anyway for an undetermined amount of time anyway for other reasons.