Spark Check

Perform self diagnostic QUICK TEST to check for ignition-related fault codes, and repair as necessary. See QUICK TEST in appropriate article:
- For OHV gasoline vehicles, see TESTS W/CODES - OHV GASOLINE.
- For OHV Flex-Fuel vehicles, see TESTS W/CODES - OHV FLEX-FUEL.
- For DOHC vehicles, see TESTS W/CODES - DOHC.
If no fault codes are retrieved, check ignition system wiring harness for damage or loose connectors. See appropriate article:
- For OHV gasoline vehicles, see WIRING DIAGRAMS - OHV GASOLINE.
- For OHV Flex-Fuel vehicles, see WIRING DIAGRAMS - FLEX-FUEL.
- For DOHC vehicles, see WIRING DIAGRAMS - DOHC.
Clean or repair connectors as necessary.
If wiring and connectors are okay, use Neon Bulb Spark Tester (D8IP-6666-A) to check for spark at each spark plug while cranking engine. If spark is strong and consistent at each spark plug (one spark per crankshaft revolution), ignition system is okay. If spark is not present, go to CIRCUIT TEST A in appropriate article:
- For OHV gasoline vehicles, see TESTS W/CODES - OHV GASOLINE.
- For OHV Flex-Fuel vehicles, see TESTS W/CODES - OHV FLEX-FUEL.
- For DOHC vehicles, see TESTS W/CODES - DOHC.