high idle

[dge61785]

I searched for about an hour and didn't really find anything like my situation.

Was out wheeling and stalled going up a hill, rolled back down and the clutch was out for a second and when I came to a stop i noticed smoke coming around the filter area of the intake, after we started it back up it idles at 2000-3000. It will not idle down at all. runs fine. any ideas??

It's a 97 Sport, 4.0 OHV, 5 spd.

Please help!

 

[Rustang©]

Could have an intake manifold leak. This would explain the smoke and the higher idle, more air is getting by than needed.

Also did you check the throttle butterfly to ensure it is in a closed position?

Let the truck run at its high idle, does it run warm or hot, if so it is most likley a manifold leak.

The only other thing i could think of would be the Idle Air Bypass Valve, not sure if thats the correct name, its located right nedxt to the throttle butterfly and is cylindrical in shape, if that goes bad your truck could idle very high.

Hope you get it fixed and this helps, a high idle is no good for the bearings or trans!

 

[dge61785]

It doesn't smoke anymore, just a quick little puff I'm guessing out the intake after it died and rolled backwards.

throttle body isn't sticking, linkage seems good.

doesn't get hot sitting at idle.

we tried unplugging the IAC? and it didn't change the idle.

Could the MAFS be messed up, could something else like the IAC or some other kind of sensor be messed up between the filter and the intake mani.

Any other suggestions??

Oh yeah, no check engine light.

 

[n0xdw]

Invest in a can of carb and choke cleaner, with it idling spray around the intake. Although it sounds like your IAC is stuck. You might try spraying some through it, also make sure nothing is holding the throttle partly open. Most vacuum leaks will cause it to run lean with a MAF, so your most likely scenario is the IAC or something holding the throttle plate from going fully shut.

 

[aldive]

The thermostat can cause the high idle speed issue.

 

[dge61785]

a friend of my boss has a computer it's gonna get hooked up to tomorrow morning. I'll update as I know..

 

[dge61785]

got it figured out later on tuesday night, the IAC was junk, so $100 later it's running good as new.