I have an 1988 t-bird, has a 302 EFI engine. I haven't started it for about 3 months. Well a couple days ago I thought I would start it up since it was a nice day. I started it up, and it was idling high, If i can remember correctly it was idling at around 1800-2000 RPM. It seemed like it was idling pretty high, and sounded like it too. I gave it gas for a sec and reved it to about 2,500 then it slowly went down to about 2000 RPMs again. Im not sure what the problem could be, but I would appreciate some help if anyone know what it could be.
okay so i cleaned the IAC, and still the same problem is occurring? Does anyone have any other solutions on what it could be?
Need to check the TPS voltage, should be approx ..75-.95v as measured from the black to the green wires. Also has it been scanned for error codes???
How do I check the TPS voltage?
Sounds like you have the same problem I had on my 87 Cougar when I got it.... I was told the IAc was toast... WRONG! I thought logically, then realized it was the TPS. Went to the wrecking yard, grabbed on for $5, set it up, worked perfect!!!
I followed advice from my brother in law who has worked as a mechanic for the state for about 15 years, and unplugged the IAC, the idle dropped to normal, and the car ran great, so I did what you did, cleaned it out, plugged it back in and the idle went way up. The I got another from a wrecking yard, did the same, so I tried a third. That's when I agve up his idea, and thought it out on my own.....