Alright, when I first pull out my 85 firebird, it runs at about 1k rpms. (Of course, because its cold). Then I bring her down the freeway for about 15 minutes at about 75 mph. At a stoplight I bring it to a stop and my idle sits at about 550 rpms, and then every 4 or so seconds, it dogs down to 450 and then back to 600 and then to 550 again where it sits at until it happens again. It shakes my car everytime that happens and I have to push harder on the brake to keep it from jumping an inch ahead everytime it does that.

Any ideas? Thanks

Also, the search button must be broke because when i searched "idle" it came with no results. !!!

 

I'd suggest starting by removing, disassembling, and cleaning the IAC. retension the spring, lube the pintle shaft, and reassemble and install it.

 

Well, I cleaned it (There had to be about 1/32 in of grease on it) and lubed it down with wd-40 and silicone. So I started it and got it warmed and came to a stop where the idle went down even lower than where it usually was and sounded like it was going to die. It sorta corrected itself to about 550 and did the same sort of pulsing. (it went down to about 400 when I didn't have any gas on it in first gear) Could this be due to the fact that I don't currently have a o2 sensor hooked up? I still need to get a new exhaust and get one installed...Or do I need to set the idle up somehow, or just buy a new IAC?

 

Anyone....