Hi again guys,

Sorry If I'm posting this in the wrong thread, fairly new to the forum and can't seem to navigate well around it yet

Just wanted to ask everyone's opinion.

Yesterday as I was driving through traffic on Canning Highway after work, something rather unusual happened for the first time, basically the car idles at 2100 rpm even at red light and when I had my foot on the brake.

Just suddenly happened and I feel a slight vibration on the clutch, when I engage on the clutch and pedal the rpm drops to normal just after 1000rpm and goes like normal but then when I slow down again approaching traffic it would again for no reason jump to 2100rpm with my foot on brake.

Again throughout this whole experience I feel a slight vibration on the clutch pedal.

Once I get to my destination, switch off the engine and 15 minutes later turn the engine on and drive again, it's normal and hasn't happen again this morning (everything was normal).

Any idea guys what could be the issue? my guess is not having a proper tune?

Quick summary, it's a 99 WRX, mods done is TBE, GD STI TMIC conversion and Manual Boost Controller.

Any ideas and recommendation is much appreciated

Thanks again guys.

Neutral switch on gearbox maybe

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Doing it for all the wagons out there

air idle control valve. located on throttle body. remove, clean, and lubricate (wd40) might
help

My guess is Idle Air Control Valve..... sticking, or on the way out.

Google how to clean them on an MY99, in short it's a case of removing it, spraying it with electrical contact cleaner, and re-installing.

It's common for them to be full or carbon and oil and shit after this many years, and they stick or fail.

Hey guys,

Sorry haven't been able to reply.

Thanks for all that info, I'll get that looked at.

Sorry for the trouble but could you guys point me where I would find this Idle Air Control Valve? possibly with a picture that would be much appreciated.

Thanks again guys

Hi Guys,

so this idle problem happened again this morning on my way to work and luckily my work is not too far from Subaru Service Centre so I took it down there, did a full diagnostic test and found that the Idle Step Motor is the culprit.

They free up the motor and it's running fine now but they say it may happen again and it may not... who knows....

But they said if it plays up again then I'm up for a new Idle Step Motor and they said it's in the vicinity of $950 ex JAPAN.

They gave me a part no if it makes any sense 22650AA240

Is there anywhere else I can pick up this part from? I don't think it should be that expensive and I've got my local mechanic that I've used and trusted for years to do the job for me if I can source out the part.

Another question would this be the same as Idle Control valve suggested earlier or it's a different part all together? if it is a different part all together, do you guys think it's worth replacing at the same time?

Thanks again guys.

Same thing, yes.

I bought a 3rd party branded unit off Ebay for $70, and it worked perfectly. My thinking was that its worth trying the $70 unit before forking out $900.