FastFox

okay here it is. My 89 mustang GT seems to lope and idle weird when I first start the car. After it warms up it is okay. I never had this problem until I had a new valve cover put on, because my old one leaked. I don't hear a noticeable vaccuum leak, but that doesn't mean there isn't one. My PCV valve is brand new. I don't know what it could be? Could my intake manifold be loose?

Please help.

primetime5.0

just double check all the vacuume lines and clean out the iac

mustang8719

Spray around intake and vaccum lines with carb cleaner and listen for the idle to change.When it does if it does there is your vaccum leak.If you indead have a leak.

88GT40

mine does that when it's cold but i know i have a vacuum leak i have tried 3 times to fix it but now i am going to order a new phenolic spacer and gasket to get it right this time. the 1inch spacer has leaked ever since i bought it so i'm goin back to the 1/2 in. because it's less headache.

88GT40

if there are no vacuum leaks than there are a couple snesors that could be causing the problem, the first is the coolant temp sensor, the 2nd is called air charge temp. sensor this temp sensor provides the computer with fuel air mixture temperature info. the computer uses the info to correct fuel flow and control fuel flow during cold enrichment(cold starts). located on a runner of the intake manifold.

chitwn64

I have a 1995 mustang gt. with no cats, & when i'm driving my car it hesitates & the "check" engine light comes on, also when I come to a stop the Idle go's up & down to the point it wants to cut off & has done it several times, can someone help!

lxman1

What code do you get when you scan for codes????

Rage91GT

Ok I am the odd ball I guess I have a 91 Gt that does the lope after it is warmed up.. Once you hit the gas it is all good but it sounds like it has a choppy cam.. Any ideas on that one?