Timing Advance

Ignition timing advance is controlled by the ECM based upon sensor input signals. If timing problems are experienced, inspect input signals for proper operation. See PIN VOLTAGE CHARTS article. Inputs that affect timing include the following:

• Camshaft or crankshaft position sensor.
• Airflow meter.
• Engine (coolant) temperature sensor.
• Idle switch.
• Start (cranking) signal.
• Battery voltage.