Hey guys. I seem to be having some kind of brain fart! I have been chasing demons in my GTA for weeks and simply cannot find the problem. Anyway, while the thing was idling (rough as usual) I decided, for whatever reason, to pull the IAC connector off. To my surprise, I guess, the idle didn't change one lick

So, my question now, is - shouldn't the idle change dramatically with the IAC disconnected while running? Car is at operating temp, by the way.

I haven't had a chance yet to go through minimum air/tps adjustment. I did that this spring and it was running fine, then all of a sudden it crapped out, so I don't think the IAC/TPS adjustment could be bad, but one of the components could be bad. Last fall I pulled the IAC apart and gave it a really good cleaning, in case someone asks

Thanks

 

well, i say to you, *** Bless, and good luck, cause i had the same problem with my 88 Iroc 350 TPI and it was something weird with the MSD dist. not working with the aftermarket ECM and hypertech chip, and some sensors were bad and it messed up the input from the TPS and IAC, but it might no make a difference because you can adjust the idle with the screw on the TB, but if you turn it too much one way or the other it might be different cause the voltage running throught will be wacky and show a idle rich/lean condition. but if i remember right it should be something like 5 volts or close, but some one will read this and probably correct me, but then again, i switched to carbed!!

 

No.

Edit to correct the second poster, the TPS should be ~.5v w/the throttle closed and <4v at WOT.

 

The IAC has a stepper motor inside and receives pulses from the ECM to open or close in increments. If your throttle opening was such that your idle was acceptable, then it won't need to change. A carburetor doesn't need constant changes in throttle opening to maintain idle speed, so why would TPI?