Started out as a problem where the motor would idle at 1k rpms just rolling down the road in drive at about 40 mph or 30mph, the idle would actually go lower as speed would go down. I found an article on how to adjust iac on tech boards and tryed it. I jumped the a and b connections on diagnostic plug in and turned the key into on position one click before starting the motor, waited 30 seconds then unplugged iac and the started the motor. adjusted the idle screw to be at about 450 or 500 rpms(i wasn't getting smooth idle, it would jump about 50 rpms up and down). then i turned the motor off, plugged the iac back in and the turned the motor back on, it was idling at about 700 in neutral and 500 in drive(still not stable). I went for a drive and it worked good, at 35 mph when letting off the gas pedal the motor would idle at 500 or so rpms. I got back home and parked, turned the motor off. After about a minuted i turned it back on and it would idle at 2k rpm constantly in neutral and 200* temp. In drive it would be at 1200 trying to take off . i redid everything as if i was adjusting iac and started the motor up after plugging in the iac and it worked correctly until turned the motor off again and started her back up. the idle was back to 2k rpms. I checked the codes and it came up with 13,22,32,34,14. I remember 13 and 22 being there before but others are new. Is iac bad and replacing it would fix all the codes or is there something else doing it? I tried to do some search for this problem but wasn't very successful. P.S. also for no reason known to me my millage went down from 18 to 15 mpg and that's combine driving with 60% highway driving. I've been in college station couple weeks ago and i was getting 15 to 16 driving in stop and go traffic. Also i used to be getting 22 mpg on a highway but obviously it's less now. The car is 89 firebird trans am with 305 TPI, headman header, 700r4 and i belive it's 2.73 limited slip, there is 127k miles on her. thanks for any help EDIT: i did found a little info that the pcv filter might cause some of my problems, i'll try it tomorrow.

 

Sounds like the same problems I had a while back, it turned out to be a bad TPS. It was reading 2.5v at idle. It supposed to read around .98v

 

the tps been replaced about three weeks ago, what kills me is why it's idling at 2000 rpm unless i go tru the whole disconnecting and reconnecting iac thing. UPDATE: i went ahead and adjusted the tps because when i replaced it it's been adjusted based on what rpm's the motor was idling at. It was at .2 instead of .54 v. Now i tried starting the motor and it was not idling at 2000 rpms and only at 1000 rpms, but it wasn't at operational temperature yet. I'll see what she does tomorrow when i go to work. I hope that 2k thing will go away