Excessively High Idle

Inspect accelerator pedal and cable for sticking.
Verify vacuum hose routing is correct.
Ensure there are no vacuum leaks.
Test ECT sensor operation.
Inspect ISC actuator for malfunction.
Inspect IAT circuit and output.
Verify correct throttle position sensor adjustment and resistance.
Inspect A/C circuit.
Ensure fuel injector operation is correct.
Ensure ECM has correct voltage supply and is properly grounded.