hey all,
i got some problems with the wrx

check engine light came on yesterday, and wen i pulleed over it just died. waited a while i started with no engine light on..
it started revving at 2.5 thou at the lights for no reason, and it also revvs up and down from 0.5 to 1.5 after going and stopping suiddenly eg red lights.

from experience does this sound like a fule pump?? or something similar, what is my best option getting it sorted out.

thanks

Sounds like fcuked Idle Air control valve

what is that? ha. is it costly?

When your engine is idling, your throttle is shut, which allows no air in. In order for the engine to keep idling, the ECU opens the idle air control valve which lets air into the manifold. If the IACV is broken, the ECU will not be able to use the IACV to control the amount of air gong into the manifold hence the erratic idle. If the throttle is shut and the IACV is also shut, the engine has no air going in at all and cannot maintain the combustion process, and then shuts down.

I have never had my IACV die on me so I am not sure how much it will cost, but I cant imagine it to be over $200 plus labour to replace.

Another possibility could be a vacuum leak... Check all your vacuum lines and intake after the AFM for and cracks or loose clamps.

I've been quoted by subaru for a IACV (MY99 WRX) for well over $600. So if possible, borrow one from some one else to try first. Are you running factory ecu? What kinda car is it? Could also be afm...

Just some thoughts...

Darren

__________________
When in doubt, Pull it out...

$600! FARK! Defnitely be better to get second hand one from a wreck or something.

98 wrx. standard engine and parts. 3" tb thats pretty much it.
so really if it is this IACV then a new ecu would be a better option if i was going to upgrade the turbo anyway??

If the IACV is gone, your gonna need to replace it prior to putting in a new ECU anyway. Im preety sure even after market ECUs still need a working IACV

Yes, if the IACV is stuffed, you will need one no matter what. However, like I said, it is possible that it is a AFM problem, even though 98's are less prone to failure then the 99's but it is still possible. I once thought I had an IACV problem but it was something completely different (after market ecu issue) so best to borrow someone elses IACV for a little while and see if it fixes it. I'm not sure if the MY98 and 99 IACV's are the same, but if they are, then I have a spare you can borrow to test.

Cheers,

Darren

__________________
When in doubt, Pull it out...

Throttle positioning sensor ?? does the same thing when its stuffed