A spark plug with a broken side electrode is not sufficient to check for spark and may lead to incorrect results. All wire colors referred to in this part relate to the colors of the ignition module wires. When working with a wiring harness, the wire must be traced back to the ignition module for proper color identification. When instructed to inspect a wiring harness, both visual inspection and a continuity test should be performed. When making measurements on a wiring harness or connector, it is good practice to wiggle the wires while measuring.
SECONDARY SPARK TEST
- Disconnect the secondary (high voltage) coil wire from the distributor cap and install a spark tester between the coil wire and ground.
Crank the engine. A good, strong spark should be noted at the spark tester. If spark is noted, but the engine will not start, check the spark plugs, spark plug wiring, and fuel system. If there is no spark at the tester:
- Check the ignition coil secondary wire resistance; it should be no more than 5,000 ohms per inch (25mm).
- Inspect the ignition coil for damage and/or carbon tracking.
- With the distributor cap removed, verify that the distributor shaft turns with the engine; if it does not, repair the engine as required.