Spark Knock/Detonation
NOTE:
Unless otherwise indicated, see SYSTEM & COMPONENT TESTING article for testing procedures.
- Check ignition timing adjustment. See ON-VEHICLE ADJUSTMENTS article.
- Check fuel injector circuits.
- Check ignition circuit.
- Check fuel pump circuit.
- Check Exhaust Gas Recirculation (EGR) system.
- Check cooling system operation.
- Check PCV system.
- Check fuel pressure regulator. See BASIC DIAGNOSTIC PROCEDURES article.
- Check ignition circuit.
- Check Camshaft Position (CMP) sensor circuit.
- Check Mass Airflow (MAF) sensor circuit.
- Check front Heated Oxygen Sensor (HO2S) circuit.
- Check ECM power supply and ground circuits.
- Check Engine Coolant Temperature (ECT) sensor circuit.
- Check knock sensor circuit.
- Check Vehicle Speed Sensor (VSS) circuit.
- Check fuel delivery system.
- Check for vacuum leaks.
- Check engine mechanical condition.
- Check EVAP system.