I have an '01 Tribute, 2.0, 5spd, FWD with an erratic high idle. Sometimes it will start and race right up to 4000rpm and stay there, or slowly drop to idle (roughly 900-1000rpm), fluctuate to 2200rpm, drop, rise. Sometimes it will start, race up to 4000rpm, drop to idle and remain there for 10 minutes until I put it in gear, come off the clutch, then race up to 4000rpm. I'm going to look at the Throttle Positioning Sensor tonight, but was wondering if anyone had any thoughts. Thanks for your time.

 

TPS is physically intact. All cable and linkage intact, not sticking. Going to check for an air control valve which I would assume is located on the throttle body.

 

I found a collapsed/crushed vacuum hose attached to the lower end of the throttle body right at the connection. This hose has a heat shield around it as it is routed around engine block. It's dried out as well - six years old and 304,000 miles on it. Could be suffocating or being the hose is dried out, too much air getting in/out if it has cracks in the wall. Not sure of the direction of air flow through that hose.

 

Intake air control valve was rusted.