Why is my car doing this?

[laserstang94]

I have a 94 gt and cant find out why it is revving so high at idle 1200 to 1300. I checked for vacuum leaks and I dont have any. Can anyone tell me what is going on here......

mods:
cold intake
equal length headers
gt40 intake with ported lower
msd billet aluminum distributor
msd ignition coil
2 chamber exhaust
off road h-pipe
power pulleys
110lph fuel pump
stock injectors

 

[HISSIN50]

Congrats on the first official [Tech] post.

More info would be helpful. What is your normal hot idle? Any recent work? Did this just happen one day or has it been gradual?
Does it idle down like it has a vac leak?

More info will help.

What happens to the idle when you disconnect the IAC?

Good luck.

 

[laserstang94]

it happened after i installed the intake manifold..........

 

[Guero]

What happens to the idle when you disconnect the IAC?

Good luck.

my idle goes lower but stays low. what does that mean. sorry for hijacking

 

[mo_dingo]

it happened after i installed the intake manifold..........

Sounds like a vacuum leak at the intake, or a line has broken....Get a vacuum gauge and see how many inches of vacuum it's pulling at idle. You could be missing something.

spraying carb cleaner around the base of the lower intake, where it meets the heads, should show you if something didn't seal right.

Did you R&R the IAC valve, or did you just leave it on?
Scott

 

[HISSIN50]

If you dont mind removing all the vac lines and sealing the intake, you can do it but put a vac gauge on one fitting. Disable the ignition/fuel system and crank the motor. Look for 3-8" hg on your gauge. Less suggests a leak.

Guero, If this was done on a hot motor, it means your IAC works but you set your idle differently than I do.

Good luck to both.

 

[laserstang94]

Sounds like a vacuum leak at the intake, or a line has broken....Get a vacuum gauge and see how many inches of vacuum it's pulling at idle. You could be missing something.

spraying carb cleaner around the base of the lower intake, where it meets the heads, should show you if something didn't seal right.

Did you R&R the IAC valve, or did you just leave it on?
Scott

you were right.....! that fixed the problem. one of my heated hoses were bad. thanks!