Comanche idle very high when starting.

[Disturbed]

About half the time I start my truck it idles very high, or maybe I should say revs very high becuase it is way above an idle speed. It does this for what seems to be a random amount of time, never seems to be the same. Once it drops down to a normal idle speed it doesn't do it again until the truck has been shut off and restarted. Doesnt seem to make a difference if it has be sitting overnight, or for 10 minutes, the whole issue seems very random. Any idea what could be causing this.

 

This truck seems to be the king of random problems. I have a random problem with the radio (aftermarket) also. It always comes on just fine. The display and all of the controls work without issue but I get no sound. The I will hit a bump and the music starts playing. but it isnt just bumps. Right turns, left turns, bumps, hitting the brakes, pressing in the clutch, all of these can cause it to come one or shut off. I am ready to tear the whole stereo system out and replace it all, I just don't have time.

[87Warrior]

Remove, inspect and clean the IAC (idle air control) on the throttle body and see if there is any change.

 

My gut was to say check the gaskets along the intake track, but since it will do it when warm and not return until shut down, I eliminated that possibility.

 

Sounds like your speakers are grounding out.