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Car Reving From Stock Idle To 2000Rpm By Itself?

R34gymjunkie

By R34gymjunkie,
in General Maintenance

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R34gymjunkie Contributor

R34gymjunkie

Posted
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Installed a boost controller tonight n car was running fine on 10psi, after giving it a bit of stick in now idles from 1000rpm right up to 2000rpm at idle by itself and while driving?? Checked for vac leaks and cnt find any? Confused :(

D.I.Y. Mik Veteran

D.I.Y. Mik

Posted
Posted

Aac valve clean?

Block off cold start valve.

Does it idle normally if you switch it off for a second then start it again?

Mine does that. Blocking the cold start valve helped but didnt fix

come to think of it... it started on mine after i installed the boost controller.

I got the HKS evc4, what one do you have?

Maybe we should unhook the boost controllers and see.

blind_elk Grand Master

blind_elk

Posted
Posted

My car revs to 2grand and back to 1200 constantly at idle not jst sit at 2000 if that helps...

My experience is that that sort of idle indicates a fairly significant air leak. It could be in the boost controller, but you need to closely inspect every vacuum hose, especially the larger ones (like PCV to rocker hose).
R34gymjunkie Contributor

R34gymjunkie

Posted
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I think it's mechanic time, I stripped nearly all pipes n hoses today on the engine to inspect them, cleaned AAC, I'm not sure witch one is the cold start valve, I tried adjusting the tps, and aic? Still got no clue :(

D.I.Y. Mik Veteran

D.I.Y. Mik

Posted
Posted

Hmmm....

After reading that id say the ECU is the problem.

With all the upgrades it needs tuning.

Well thats next on my list anyway, im just trying to get as much sorted out as i can before i get the ECU and tune.

So i might let the mechanic sort this one out.

mattis96 Proficient

mattis96

Posted
Posted

wow i have exactly the same problem!!! It only happens on first start up and has to warm up to go back to normal. after i turn the car off and back on again it idles at 1000, it is very annoying, and this can be just sitting idling there, warm up for 10 mins with touching nothing, turn car off, turn car back on again with touching nothing and it is fine.

nothing gets touched or changed except it is restarted once warm and its fine, though if its not warm enough the idle creeps back up to 2500 until restarted again...

  • 1 month later...
GTR260 Proficient

GTR260

Posted
Posted

The car is designed to do what it is doing, the ecu is seeing the revs rising whilst the tps is at 0 and goes into decel to control the revs once the revs are low enough go back to normal and the revs climb again. It will keep repeating the process! My rb26 was doing this for ages and no mechanic could fix it! I end up finding the problem myself, mine was a bent butterfly on cylinder 1, ur engine is getting a significant leak from somewhere between the throttle and the head. Could be buggered throttle shaft seals or any of the gaskets between there snd the head! Even the injector seals! Either way its a air leak.

How much boost were u running when it happened? What engine and where are u? I could give u a hand to try fix it if u r local to me

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