PericoSC

I need some help figuring out why my idle control valve is stuck closed. I ran a lead from the battery to the valve and confirmed that it is opening and closing I would like to know what else I can do to diagnose this problem.

Also, ECU was just rebuilt

Ali SC3

iTrader: (10)

how does the connector look, is there a crack on the side?? if so replace the connector.

PericoSC

Connector is perfectly fine on all sides, and no smudge inside. Forgot to mention that my old iacv was having this problem and I replaced it, but it's the same issue with the replacement, I install it with the pin pushed in and it idles very very high. But after a few starts it works it's way open and just stays there.

Ali SC3

iTrader: (10)

maybe its the rebuilt ecu or something like a coolant sensor, hard to tell if its moving when you apply power in both directions and sticks on the car, then It sounds like an electrical issue which is why I mentioned the connector, have had that happen before. I am assuming you cleaned the passages already. If its not very smooth in moving maybe apply some wd40 to it and work it loose, they should be able to turn without much effort.

PericoSC

I already replaced the coolant temperature sensor but no I have not yet cleaned any passages.

Ali SC3

iTrader: (10)

well since you have an sc300, its built into the throttle body. remove the IACV again and clean out the air passages in the throttle body where the plunger makes contact when closed. sometimes if there is too much stuff there it can stick.

PericoSC

Ok thanks, will do so when I get home tonight and post the results.

PericoSC

So I cleaned the passages and nothing changed.....can someone tell me how to check that the iacv is receiving signal from the ECU.

PericoSC

So I took a test light and it came up that all the wires are getting voltage, so I'm lost as to why the IAC is stuck.

Ali SC3

iTrader: (10)

its not that they just get voltage the ecu has to ground them in the right manner to open and close.
I would think the ecu is not rebuilt probably or was just too bad to repair. I would try a spare if possible.
are there any other issues. You can unplug the IACV in the closed position but then you will have to throttle it a bit when you start it each time.

PericoSC

No other issues besides cold start issues , what I did was I pushed the pin about halfway and disconnected it so it idles better but that doesn't fix the problem, I guess I'll try another ecu if I can find one and go from there.

ChaseMcCla

Did you ever find a fix having the same issue I think