Fiero A/C Idle Problem

Asked by echohawk70 Jul 19, 2011 at 05:39 AM about the 1988 Pontiac Fiero Formula

Question type: Maintenance & Repair

I own an 88 Formula, manual. Right when I turn on my compressor sometimes it
drops my idle so low it kills the car. This happens usually when I turn on the
compressor right when I turn the car on, but sometimes when I down shift from
third to second, or if I push the clutch in, in first if Im above maybe 2000rpm.
Sometimes it dies even in higher gears, though, I just think i notice it more in the
lower ones. I've replaced the IAC in hopes that it would fix the problem, but
didn't. Any ideas?

20,115

Mike answered 13 years ago

Couple of things pop into mind right away. Check the throttle bore for coking ( carbon deposits ) Check to see if the computer is seeing the AC "ON" signal If everything looks okay - Try a battery clear - Remove both terminals on the battery and hold them together for about 30 seconds and reconnect - Start the car and immediately turn the steering wheel all the way to the stop and hold there for a few seconds and straighten.With Out the AC on take the car for a ride at 40 miles an hour for about 5 minutes and return. Then Put AC on - And turn steering wheel all the way to the stop and hold for a few seconds. Straigten wheel and take it for a ride and see how it does now.

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Steve answered 13 years ago

The idle air step motor is located on the throttle body, it is a good possibility it has quit working or has gotten stuck. It's job is to increase and decrease the amount of air that leaks around the throttle plate when the throttle is closed and the engine comes under load like from the A/C starting and stopping.

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