Spark Test
NOTE:
Before performing spark test, ensure ignitor is properly grounded.
- Disconnect negative battery cable. Remove oil filler cap. Remove timing belt cover and gasket, located above ignition coils. See Fig 1.
- Remove PCV hoses. Disconnect engine wiring clamps on ignition coils. Disconnect electrical connectors from ignition coils.
- Remove bolts and ignition coil assemblies. Reconnect negative battery cable and electrical connectors on ignition coils.
- Remove spark plugs. Install spark plug on each ignition coil. Ground spark plug against cylinder block.CAUTION: To prevent gasoline from being injected, DO NOT crank engine for longer than 2 seconds.
- Crank engine and check for spark. If spark does not occur, check ignition coil and ignitor electrical connections.
- If electrical connections are okay, turn ignition on. Ensure voltage exists at ignition coil positive terminal. If voltage exists, proceed to step 7). If voltage does not exist, check wiring between ignition switch, ignition coil and ignitor. Refer to the WIRING DIAGRAMS article for wiring circuit.
- Check ignition coil resistance. See IGNITION COIL RESISTANCE under IGNITION CHECKS (SUPRA TURBO) . Replace ignition coil if resistance is not within specification. If ignition coil resistance is within specification, proceed to step 8).
- Check resistance of camshaft position sensors and crankshaft position sensor. See CAMSHAFT POSITION SENSOR and CRANKSHAFT POSITION SENSOR under IGNITION CHECKS (SUPRA TURBO).
- Replace camshaft position sensor or crankshaft position sensor if resistance is not within specification. If camshaft position sensor and crankshaft position sensor resistance values are within specification, proceed to step 10).
- Check ignition IGT signal from ECM. See appropriate DIAGNOSTIC TROUBLE CODE 14 chart in the TESTS W/CODES article. If IGT signal is okay, replace ignitor. Reinstall spark plugs, ignition coils, timing belt cover and gasket.