Not sure where to start here, but my 2000 GT will idle up to 2,000RPM, then down to 800, then maybe back to 1500. It varies. sometime it will die. anyone know what could cause it to Idle like this?

 

Also If i rev it a little, when I let off, it stays reved for a few secs before it starts to idle again..

 

has it thrown a code?

 

sounds like your IAC (Idle air Control Valve)

 

That's what it was, I cleaned it up, runs better. Just a temp fix till I get a new one.

 

Here's a question. I had that code, got a new IAC valve, but the problem didn't change. Idles between 1000-1400 RPMs. Am I looking for a vacuum leak at this point? Anywhere in particular I should be looking? I tried spraying soapy water on seams/joints, but never saw any bubbles..

 

if you have a constant idle at that then you should keep looking for a vaccuum leak. if you still can't find one adjust your idle set screw and see how it runs then. The vaccuum lines you really should be looking at are the ones going to the plenum or the connections at the plenum.

 

So start at the plenum and follow the vacuum lines out from there? I'll see what I can turn up. Thanks.