Originally Posted by Sidney

The Throttle body needs cleaning:

To clean the throttle body remove the air intake hose and examine the intake and throttle body for excessive carbon build up if found then buy a can of throttle body cleaner labeled "safe on oxygen sensors,TPS's and catalytic converters" do not use carb cleaner make sure your engine is fully warmed up prior to using as when the throttle body is hot it dissolves the carbon easily and quickly.The labels usually specify to park the vehicle at ground level (0 degrees,no inclination) and have the engine running but I disagree I instead park the vehicle on a hill facing down and shut the engine off and hold a rag below the lip of the throttle body and poor the stuff and use a tooth brush.

If problem persists the TPS then needs adjusting:

Toyota 22RE Throttle Position Sensor

and then use a timing light to make sure your timing does not get retarded and cause overheat episodes.

Toyota 22RE Throttle Position Sensor

Sidney