Brad Peterson

So as the title says, my 944 Turbo has a High idle, sounds like its about to stall on acceleration and hesitates, but loses the problem at higher speeds (past 2nd gear usually). I've recently replaced most of the vacuum lines, so a vacuum leak is unlikely, and this problem started very suddenly with the hesitation, but the high idle has always happened as long as I've had it, when adjusted to factory idle, the car sounds like it is bout to stall. I had to adjust idle significantly after replacing a failed fuel pump, to get it up to around 1000RPM, and it sticks to 1200RPM when hot. I know this forum is very knoweledgeable, and was hoping for some suggestions as to what is wrong.

Scott H

Vacuum leaks can happen from things besides just the hoses, the TB can leak, the ISV can leak, the fittings on the intake manifold can leak, so can other things that I'm sure I'm forgetting right now. You'll need to test the whole system and listen for leaks and then fix the culprit(s). Arnnwrox has a good write up on how to do it/what to look for: http://www.arnnworx.com/catalog/inde...d=23&chapter=2

If I had to bet I'd say your ISV is leaking, it's pretty common and can be easily fixed with some JB Weld. Still, test the whole system, you might find a few leaks.

Brad Peterson

Oh, that makes sense, thanks for pointing me the right way, I had no idea that the TB or ISV could have a vacuum leak, but it definitely makes sense, and I'll definitely get on testing the whole system.