Toyota Repair: Idle problem and overheating problem, clutch fan, toyota pickup

Question
1989 Toyota Pickup 4WD, 5 Speed, 22RE, no AC,
110000 miles.
With engine warm idling, high idle kicks on and off when brake is applied with trans. in neutral or clutch depressed.  What would cause this?
Thermostat has been recently changed, still have overheating problem...?  

Answer
The Ecu will compensate for an electrical load by raising the idle.
If the idle is surging you may have air in the cooling system.
If the air reaches the sensor, the Ecu gets a false signal and cant properly adjust the idle and it surges.
If you changed the T stat and its still overheating, you obviously have another problem.
Does it overheat on the road or at idle?
Have you checked the clutch fan?



Mike