My DSM is idling too high. Can you help? Options

[JohnnyWadd]

Hey, guys. Ever since I put my car together after the theft, it's been idling too high. I had to put a different throttle body on her, so I figured it was just the BISS. I tried spinning that in, and it didn't help. I bottomed the screw out, and it still idled at around 1900 rpm's. I woulda thought that screwing it all the way in woulda killed it.

Anyway, before I jump into trying to diagnose this problem, I want to get as much background as possible. If I'm going to start searching, I want to search it all. So, I was wondering if you guys could tell me what to check. Can you guys list as many things as possible that control idle speed? That way, when I jump into it, I'll be able to check everything at the same time. I'd rather do it that way than check one thing, quit till later, check another thing, quit till later, and on and on. Ya catch my drift?

Anyway, if you guys can help me create a list of things to check to back my idle down, I'd appreciate it. By the way, I drive a 1991 Talon TSi FWD 2.0L Turbo.

Thanks
Jon

[The Iron Goat]

Buddy, you probably just have a common leak at the throttle body gasket. Your smoke test isn't a good way to check for boost leaks at all. You obviously had to do that sitting in a garage, correct? Well, boost leaks need to be checked with the system pressurized, not at idle. The air leak I'm talking about would only be sucking air into the intake manifold, and therefore, the smoke wouldn't come pouring out of the area.

Do the ISC test found at www.crebotech.com

Put a multimeter on the plug end of the ISC and check for voltage. Quit messing with different ISCs, you're only wasting time.

The TB gasket is like $3. Go buy one, replace it, and see what happens.