Ok so here's the deal I have a 1988 yota 4 runner 22rec just put in a fresh engine. I fought some coolant leak gremlins I got those squared away and ended up with the notorious erratic idle after having removed the throttle body manifold several times (I am on brand new never used gaskets.) When I isolate the IACV it idles fine. I have checked for intake leaks via map gas and break cleaner. The only thing that cures the erratic idle is isolating the IACV, I have burped the sys. countless times and have brought the truck to normal op. temp. several times. Is this a possible symptom of another problem or do I just need to bite the bullet and buy a IACV???? I am a noob and there are several threads but I really never found a cure or answer for my particular problem.

 

An idle air control valve can go bad and cause a high idle. Try removing the IAC and take it a part and see if you can fix it, if not see if you can find a used one, because a new one is around two hundred dollars.

 

I have a junker IAC on hand...that will be my next step I think...the truck works perfect when the current IAC is isolated.

 

rain and hail right now.....redlands

 

Ha haaa I replaced the IAC with a junkyard IAC and problem solved

 

Good deal, sometimes used parts can save you a lot of money,glad you got it fixed.

 

The rain just stopped so now I am going out on a shakedown run
Thanks for the help.