i have been having a multitude of problems with the idle.
so i fabbed up a plate to go under the iac and close it off.
it seems to drive so much better now.

is it safe to do?
how much does this circuit effect fuel/air mixture? thats the only risk i was
thinking. maybe when i get the time or money i'll actually fix it but for now i just want to drive it without it.

 

Well if it will idle with the iac blocked off then that tells me you have a pretty good size vacuum leak. I would fix that and then the Iac system will work as designed.

 

I have had my iAC disconnected for the best part of 7 years now, and the truck hasnt missed a beat. It used to go to high idle when the clutch was pushed in, we found after a couple of hours of searching thru the codes that apparantly there was a short in the wire harness somewhere so I just disconnected and havent looked back. I raised the idle by turning the screw that says do not touch and even with the AC on which the IAC raises the idle for it was not a problem. so you can leave it in but disconnected as I have and should not have any problems.

 

I had an old Tempo with high idle problems. I replaced everything that that my repair manual said was the cause (sometimes twice) but the high idle problem still persisted. I gave up and wired a toggle switch to the IAC so that I could turn the IAC on to start the engine and then turn it off after things warmed up. I turned the idle up with the adjustment screw just fast enough so that it would stay running in drive. My daughter ran it that way for about 2 years with no problems at all.

 

with it bypassed the idle drops to only a few hundred rpms and will die. i have the idle screw way turned up and its working real well for me. this totally rules out a vacuum leak possibility. thanks for the reply, i'm definitely never running the iac anymore.

 

That is correct, if you disconnect or plug of the IAC, the engine should die. If it keeps running or idles high, you have a vacuum leak somewhere.