Sounds like a vacuum leak. There is a hose on the back of the intake manifold that hooks to the vacuum line for the auto hubs. It runs along the firewall. If it has designated, the idle will be high.

 

I think it wants to go to Florida for the winter. When I turn off the blower fan it stops acting up. Then again, I was starting up a hill in first and it revved out of control, 6500 until I turned it off. I started it again and back up to 6500. Took the cover off the top, checked the throttle, spring was good, tried it again and it was fine. Now that the cover is off I can check the vacuum line, but it's cold out there.
Something seems to be communicating bad information.

 

I think it wants to go to Florida for the winter. When I turn off the blower fan it stops acting up. Then again, I was starting up a hill in first and it revved out of control, 6500 until I turned it off. I started it again and back up to 6500. Took the cover off the top, checked the throttle, spring was good, tried it again and it was fine. Now that the cover is off I can check the vacuum line, but it's cold out there.
Something seems to be communicating bad information.

I don't understand that part in bold - if its a manual trans and you're going uphill and the revs take off, then the clutch must be slipping bad.

The high idle is usually a vacuum leak and/or the IAC.

Sometimes you can get away with cleaning the IAC with carb cleaner.

 

In addition to vacuum lines, I would check pull off the metal intake plenum (where the rubber hose from the MAF connects to) unbolt from the TB / remove, and clean the throttle body - would be suspect of carbon / gunk on the butterfly plates, making it stick. Use carb cleaner and a nylon brush (or toothbrush) to really get in there and clean them up..

Have a helper operate the gas pedal, engine off, after cleaning - verify the TB butterfly plates and cable are working smooth.

If not that, it sounds like a major vacuum leak - would also check the PCV valve & hose, especially where the PCV hose connects to the upper intake manifold port.

Of course, the IAC valve is also suspect, I would check that area, and the plastic resonator -> hose mounted on top of the metal intake plenum. Pull and clean if suspect, be careful of the gasket on the IAC.. I'd bring the entire metal intake plenum inside to a heated area, let warm up to room temp. before cleaning.

Regards,
GottaCruise

 

spontaneous high idle

I had a problem with the 1999 Kia Sportage, 4dr, 2WD suddenly revving to high idle too. The engine would also rev too low, shudder and stall. I cleaned the Idle Air Control valve, which was VERY dirty inside, and the problem has been resolved.