Wierd idle problem

[sixty9boss302]

Hey so i did a big tuneup on my 91 stang this weekend and replaced all the normal stuff and a few other things. I took it out for a little test ride and when i put the clutch in while rolling around in 1st or 2nd gear the RPM's jump up to like 2G or 2.5G and they stay there and i have to shut the car off to get it to reset and then in a couple minutes it does it all ovfer again. Tomorro, i am going to try to check the voltage of the TPS or and swet it to around .94-.95 volts. and i will check the IAC, but i dont know what i would be looking for with the IAC. I cleaned out my TB when i tuned the car up, so i was thinking that might have something to do with it. The car also idled quite high (about 1100 rpm) so i was also going to mess with the idle screw and see if i could straighten that out. Thanx in advance for all the advice or help....later

 

[rdksek844]

I had the exact same problem, but it was my butterfly not completely closing that was causing it. There was a film just behind the Butterfly keeping it open. Try manually closing the throttle at the tb by hand while its high and if the idle goes down then thats your problem, if not try cleaning the iac. Sometimes they stick open and cause high idle. The way to test is, while the idle is high pull the cable off of the iac and the engine should die, If it doesnt, then the iac is stuck or the the butterfly is stuck.

 

[sixty9boss302]

Thanks for the info rdksek844. I will definately try that tomorro. I thought that it might be the butterfly valve stickin too, but i just cleaned the thing out and it seemed to be moving well. Who knows but i will try what you said and i hope that will take care of it... Thanks again for the advice. Later

 

[jrichker]

See http://www.members.tripod.com/sparkplugs/idle.htm or http://www.mightyap.com/index.htm for some help on your surging idle.

Both sites point to bad TPS sensors as being the culprit in the surging idle that goes high and sticks until you shut off the engine.

 

[sixty9boss302]

Yo nick ya gotta remember what you're username was so you can stop posting under my name. People are gonna start thinkin i own a 91 gt with lots of problems.