High idle need help

Try this out...Kinda sounds like the symptoms my friend's GT had a while back,his idle would hang sometimes and then it turned into an all the time thing and this did the trick...plus it's free!

Ten Pin

-Milt

some also use propane to find leaks (i have not done it - be careful with whatever method you use).

yep, idle changing when spraying indicates you have found a leak.
the puter has the idle hang and fall slowly (like a vac leak) while rolling. if it hangs while standing still, that is not normal. some cars are worse than others with the hanging idle upon slowing (using input from the speed sensor). one of my other cars is bad with it hanging while slowing.

you could also pull codes for fun, to see if anything is stuck in KAM.

good luck.