Idle Problem Fixed By Red-lining Car?

[andy panda]

Ok, so i have an r33 gtst series2, it's got a stock ECU and it usually runs like a dream, however today it was idling at 1,700 rpm and when i was slowing down and the revs got low enough it would literally accelerate forwards by itself. Also when i put the clutch in while rolling it would go down to 1000 rpm, rev up to 2000 rpm by itself, drop down and nearly stall, and continue doing that until i was stationary. The weird thing is though, i floored it in 2nd and red-lined it, and after that it was perfectly fine...

What an earth could have caused this? Even though it's fixed itself now, should i be worried? If it was the ECU playing up it won't matter too much as i'm putting a PFC in it next weekend... Still a bit daunting that it did that, then fixed itself with a thrashing :S

[Prue]

Might have been a little vacume leak, did you have the aircon on by any chance, my 33 would do that if I turned the a/c switch on by accident after ages of not using it.

[andy panda]

Don't think it was the a/c, i tried turning the a/c on n off a couple times to see if it fixed it, it didnt.. and according to my vac gauge it was sitting at the same spot as it usually does, who knows how accurate that would be though -.-

[XRATED]

dirty idle control valve....

[-_-StRyDeR-_-]

dirty idle control valve....

+1

clean it with some carby cleaner or something and it wont idle hunt.