High Idle Speed

Check accelerator linkage.
Check power steering idle-up circuit (if equipped).
Check A/C idle-up circuit (if equipped).
Check idle speed control valve (if equipped) or auxiliary air valve (if equipped) and wiring.
Check variable induction system (if equipped).
Ensure ignition timing is correct.
Check throttle position sensor.
Check for high fuel pressure.
Check for leakage at cold start injector or fuel injectors.
Check power to ECU via fusible links, fuses and EFI main relay.
Check airflow meter, coolant temperature sensor and air temperature sensor.
Check injection signal circuit.