Ok, I have an 89 firebird formula with the 350 tpi and it idles weird. First of all yes, I tried cleaning the iac, properly setting idle, changing tps to.054 volts. That was all I could think of. Here's my symptoms, I start it up, it wants to die when cold, like the iac isn't opening, a few mins later it will stay running, then once it warms up it idles at 1400 rpm, its like the idles for warmed up, and cold start are backwards. Can anybody recommend anything else to check or what the problem may be? I know the iac could be bad but for a $100 electrical part, I don't want to change it unless I know its the problem. Thanks in advance, Garrett.

 

if the coolant temp sensor is bad, or not plugged in it causes that to happen. i hooked up a snap on machine to my car, it was reading -39 degrees. wouldnt stay running for the life of me when it was cold. once it got up to temp it ran better.. just not great. replaced coolant temp sensor, all of that went away. i know the 305 tpi has them underneath the hose under the throttlebody. not to sure if the 350 tpi's were the same set up, id assume for the most part they were. good luck.

 

Yeah its in that same spot, that would make sense why it would run like that, ill try to swap it out and post back

 

Ok, replaced the coolant temp sensor, and it seemed better for a day now its still stalling when cold. Anymore idle problem ideas? Edit: high idle when hot, and low idle when cold still a problem