YogSaahoth

iTrader: (9)

Base idle set screw I think. Anyway its a little screw that adjusts idle rpm, don't mess with it. Let me guess...cold start is fine but once car is warm idle starts to act screwy. My car has been doing it for about 4 years. It's pretty common but no one really knows how to fix it since it "could" be caused by a million things, and in the big scheme of things it's the least of an Evo owner's concern. By all means, have STM check it out. In most cases everyone suspects the IAC motor, which is a $400 oem part. Not really in your best interest to replace it on a suspicion. There's a few threads open on the topic. Kaj is a member of the gang trying to figure it out so his list is accurate. I'm starting with replacing fuel system components because mine are old. I'll play with the IAC motor too to see if I can rig it to function properly. Worst case scenario would be alternator or fuel system items. Since your fuel system is stock (as far as you know) it's very rare or pretty much nonexistent for fuel components to spontaneously crap the bed and take your motor with it.

Since the car is new to you, have STM check it all out, making a note of this idle problem. It's very likely the previous owner did not disclose the full history of the car to you. No offense to anyone, it's just the business we're in. Buy an Evo, get a mysterious bucket of bolts with lots of baggage

kaj

iTrader: (60)

speaking of the alternator:

i recently had my car randomly going lean. it turned out to be a loose alternator wire. LOL. but that was at idle, intermittently. not quite the problem OP is describing. but i thought i'd mention it because you did and i JUST had the problem LOL. small world.

OT topic, sorry.

but yeah.. it can be sooooo many things. we gotta start somewhere, i suppose.

drive955i

iTrader: (6)

This all sounds pretty familiar...OP, do you have an aftermarket intake pipe, and still use the MAF? I just recently installed the Buschur Racing intake pipe with MAF and recirculation port, and all of a sudden, now I have warm idle issues. I have worked on a Porsche 911 type 996 that uses a system nearly identical to ours (throttle cable with idle control valve, and Mass Airflow meter) that had an aftermarket air intake system, and his car would stall when at higher RPMs and pushing the clutch in to let the engine idle. Putting the stock airbox back on fixed his problem. My guess is that the MAF is so close to the filter that the air hasn't settled to a steady stream before it gets to the meter, so it's making very inaccurate air flow readings that are compounded by the low air speed at idle. You may be able to get it tuned out. If not, then either altering the intake, switching to stock, or going speed density may resolve this issue. On the other hand, if you still have the stock box, then just disregard this rambling!

kelsie howg

hey. I’m having more idle dips lately to the point of stalling.
i recently changed my spark plugs but with NGK .
i cleaned my maf also

Thanks!

youra6

​​​​​​​The VB STIs would have been a beast had they actually made one, but nope they hamstrung the FA24 with the same glass transmission as on the VA WRX's. What a shame.

kaj

iTrader: (60)

Yeah. I don't understand any of that, either. ​​​​​​​