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High idle GTR

Dash

By Dash,
in General Maintenance

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seeyagtr Enthusiast

seeyagtr

Posted
Posted

I had the say problem after my rebuild. cleaned of all carbon build up and idle was going up to 1500-1600 rpm. I could not find any air leaks and the hoses were all correct. At the back of the intake houseing there are the air by pass hoses that feed the aac and the cold start valve with air to bypass the trottles, blocked of these hoses to make sure that the vave were not stuck open (the rpm should drop). The only way i got the rpm down was to readjust the main throttle stops them selfs and then the tps switch. It is now at 950.

Godzilla32 Veteran

Godzilla32

Posted
Posted

The guy working on my car said he got the idle down to 950 when the oil is cold but after its warmed up its up around 1000 then if you boost it it gets upto 1100. I dunno he said it could be the oil??? Im using motul 4100 turbo light

The Dan Grand Master

The Dan

Posted
Posted
My R32 GTR is idling high too but thats after i took the whole intake collector off..a way to see if you have leaks is by spraying aero start. It will make the revs pick up when and if there is a leak around your mannifold etc..Mine hasen't shown any sign of that when i tried it but it can get as high as 1900rpm after driving...i took off my AAC valve and cleaned it out i will get a new gasket for it but i dont think thats the problem..Also since this happened i lost all boost..I thought a vacuum line could be the problem..seems more like the wastegates arent closing to build boost than a turbo failure...So i need help with this too..how can i test the stock boost control solinoid...?? Any ideas? i have a completley stock GTR. Thanks

You need what is called a mightyvac.

You can apply vacuum or pressure to the actuator and test what pressure it takes to activate the arm.

The Dan Grand Master

The Dan

Posted
Posted

all of you sound like you are having the same problem.

The throttle body should not contain any carbon build up. It should be clean at all times or whenever possible. Any crap stuck in there will cause air to be able to pass and will effect the idle.

However, when you clean your T/body, it is very important not to just spray throttle body clean or carby clean straight into the throttle body. Doing this will stuff the TPS.

You need to spray onto a rag and use the rag to clean the butterflies.

On the high idle side of things. The TPS should not have to be adjusted!

Do not move it unless you have the correct testing equipment to set it properly.

To just turn it in the hope of good results is wrong.

If you have the test specs from the manual then use them to check voltage and such. This will tell you if the TPS is stuck on wide open throttle, which it probably is.

No matter what you do to the AAC valve, it won't bring it to correct idle.

All of the above posts are good for maintenance anyway so do them also.

If the TPS tests bad, throw it away and get another. Simple.

Have you tried cleaning your AFM? Sometimes this can also effect your idle.

If you don't have the testing specs, PM me and I'll give em to ya.

Hope this helps.

The other thing is.....

About the boost guage reading. Your guage should read between roughly 15hg-20hg Which is -0.5 - -0.7bar

Any lower than 15hg and you have a vacuum leak somewhere. Or your manifold is not getting enough. I would explain but it is irrelevant.

  • 2 weeks later...
mabru Enthusiast

mabru

Posted
Posted

To add a little more to this, the TPS voltage should be approx 0.5volts with the throttle closed. Moving it just a millimeter will change this value by quite a bit so test it, move it, test it, move it. Check base timing since advance equals faster idle. As said before, clean the AAC out. If all these things checkout and the idle is still high, simply adjust the idle speed and back it down a bit. Unplug the AAC and turn the screw on the side clockwise.

My 2c

-Matt

Dash Enthusiast

Dash

Posted
  • Author
Posted

I've had this fixed for a while now

One of the hoses leading to the air reg had a small split

Very simple but time consuming fix as I hadn't been able to find it till I pulled the manifold off.Gave me a good chance to inspect everything and there was bugger all carbon buildup on anthing which was good.

The TPS on a GTR is mounted on the manifold not on the throttle bodies so theres no chance of spraying it when cleaning.

Thanks for all the advice, really happy its fixed.

  • 1 year later...
mattems Newbie

mattems

Posted
Posted

i have an r33 and im getting weird idle probs also, the car was sometimes stalling becuase of extremely low revs but since yesterday it is idleing at around 1300 - 1400 rpm, with the occasional rpm spike, but will never drop below 1300rpm

im taking it to the local performance shop for a checkup, ill let you know what they find.

cheers

(if anyone has any ideas, let me know)!

:geek:

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