With the AC on (max or normal) the idle goes up and down from 900 to 1300. As soon as the AC is off, idle is normal (too damn hot not to have AC on ) Truck seems fine when driving. No error codes when I plugged in a reader.

Thanks,

Mike


'01 SuperCrew, 157,000 miles

 

Replace the IAC valve and reset the computer.

Steve

 

Sounds like the compressor is kicking on and off. My truck had a similar problem, and it turned out to be because it was low on r134. Go to Wal Mart or your local auto parts store and pick up a can with the gauge already on it so you can check it and gas it up if needed.

 

Of course the compressor is kicking on and off - it is supposed to.

It's the IAC valve's job to stabilize the idle speed including at compressor engagement/disengagement.

If the refrigerant charge were low, usually due to a leak, the A/C clutch will simply short-cycle, but won't cause the idle speed to jump 400 RPM.

Steve

 

My idle sure jumped around when I was low on refrigerant and it kicked on and off. Hell, the truck would even try to jump forward at stop lights sometimes. After recharging it, it hasn't happened since.