I have a 1995 Ford Escort 1.9L with about 157000 miles on the car and approx. 4000 miles on the motor. The motor and trans. Was rebuilt before I got it. My problem is, when it is started on a hot engine, after about 3 seconds the idle races up to about 3500 RPM and stays there for about five minutes before returning to normal. It then idles alittle low while in gear. The cooling fan also stays on high a few minutes after start-up (cold or hot). The idle does not do this on a cold start. The idle is ok afterwards as long as I don't kill it and restart. I have replaced the idle air control valve, engine temp. Switch, and mass air flow sensor. I am unable to get any codes from computor and the engine light does not come on. The circuits seem ok and no vacum leaks. The o2 sensor checked ok. Idle will return to normal when the mass air flow sensor is unplugged and go back up again when plugged back in, although not as high? Any more suggestions would be appreciated!