1996 Isuzu Rodeo • 6 cylinder 2WD Automatic • 143,643 miles

My question is I have a 1996 Isuzu Rodeo and when I start the truck the Idle is high and then I turn it off and then start it again and its ok, but once I start driving it and get to a red light its start idleing high again. Tonight it would not stop, I drove for 20 minutes and still not stopping. Not sure what is going on with this. When I get to the red light is like the truck wants to keep going. I hope you can help me cause I am at a lose here. With this.
March 25, 2011.

Try cleaning out the idle air control valve and see what happens

Mar 25, 2011.
Check the radiator coolant level. Low coolant level could cause that as well.

Mar 25, 2011.