catch_15

So when I go to start my car for the first time of the day, it does just fine, no problem. But if I shut it off and don't let it cool all the way down, which usually takes an hour or two, it acts up. When I go to start it back up, it will stumble and then all the sudden fire up, but then it will idle at 2500 rpm until I put some miles on it, and then it settles down again. Has anybody else had this problem? It's driving me crazy.

catch_15

Come on guys....nothing? No ideas?

99BlackPonyGT

try cleaning your IAC....ive never heard of it causing that, but ive had it cause the opposite, a real low idle....worth a shot, only takes 5minutes

08Steeda

Funny you mention it. My 99 used to do that too! Especially if I went for a short run, like to the store after it had sat for hours. Run into the store then back out and then I would have to crank longer or twice to get it to catch.

Dealership said there was nothing wrong with it.

Never did find the problem. Although I had someone tell me that it had to do with the fuel system and the car not burning off everything and the vapors being recollected or something like that. Maybe one of the more knowledgable people know what I am describing.

But it had to to with gas vapors and collecting them to reuse or something like that.

But then it could have been BS. I am an IT geek not as knowledgable about todays cars!

99BlackPonyGT

my car would run fine at start up but then if i stopped for gas or something and then went to fire the car back it up it would barely start and ide have to feather the gas for a few seconds to keep it running.... it was just the IAC, just cleaned it out with some carb cleaner and it ran just fine after that...probably all that was wrong on your 99

08Steeda

Probably right! Glad you could find it!

My 99 has been gone for a long time now. I had a 2005 GT now my 2008 Steeda!

kmann717

i get the same crap with my 02 GT except the 2500RPM idle. also what does IAC stand for?

945LSTANG

Idle Air Control

Dan04COBRA

Idle Air Control Valve

It could be the reason for your funny idle. Your TPS could also be a culprit.

catch_15

Ok, so I swapped my buddy's IAC with mine and it's still doing the same thing. If I posted a video showing what it does, do you guys think that would help any? Any ideas are appreciated.