high idle when air outside is above 80 degrees.

[ocjmakaveli]

My car 92 lumina 3.1 seems to have developed a problem lately which had gone away for a while after i replaced my iac valve and map sensor.

Whenever i start the car in the daytime above 80 degrees outside it will idle really high about 1500 to 2000 sometimes and it will only go down to 1200 when i put it in drive it will stay between 800-1000 mostly 1000 though. Yet if i drive the car when its colder outside the car idles at 1000 or less and drives fine although it usually does feel a little on the high side of the idle.

The other thing is that i did get a code 22 about tps sensor but do you guys think this could have anything to do with this? There is a weak spot so to speak when i lightly tap the pedal in idle i mean just lightly tap and let go the idle goes down to 500 and almost stalls i think this might be because of the tps but otherwise the car runs ok.

Teh high idle is something i want to fix because i always have to shift it while its idling high and already replaced the top mounts once because of the high idle making the trans engage very roughly i also want to avoid trans damage etc.

I have no vacuum leaks i am sure of that i think its some sensor that isnt acting right. Its also harder to start the car when the air is warmer outside rather then when the air is cold.

Could it be some sensor that gets hot although the above usually happens when the car is started for the first time in the day nto having been run it usually acts a certain way depending on outside temp.

The other thing is you can feel the car fight the brakes a little sometimes because the idle doesnt always come down how it should it wants to idle at about 1000rpm so when braking its not always the best and you can feel it pulling a little when at a stop.

after replacing my iac valve with a junkyard one the car ran perfect but after 3-4 days it started acting up again so i replaced the oxygen sensor which was loose to begin with

i've cleaned the throttle body and iac passages checked for vacuum leaks with wd-40 and similar the vacuum gauge gave me a reading of about 17 steady.

i didnt want to replace the tps sensor yet because its hard to get to since the metal tube is in the way of it.

the cars idle just wont go down below 1000 when in park sometimes its scary because itll start up at 1200 and then it goes up slowly about every 3 seconds up until about 1800 then i have to step on teh gas so itll go down to about 1200 again and settle but then itll almost stall and go up again to 1200 then stall and go up again to 1200 it fluctuates between 700-1200 on the bad times.

i noticed to when i step on the brake at idle itll jump from 700 to 800 when i let go of the brake

otherwise the idle is just out of control