Chart C-4D-2 - Ignition System Check
NOTE:
Test numbers refer to numbers on diagnostic chart.
CAUTION:
When handling secondary spark plug leads with engine running, use insulated pliers to prevent possible electrical shock.
- If engine misfire occurs at idle, see CHART C-4D-1. A spark tester must be used to verify adequate available secondary voltage at spark plug. Spark should jump test gap on all 4 leads. This simulates a load condition.
- If spark jumps test gap after grounding opposite plug wire, excessive resistance exists in plug that was by-passed. A faulty or poor connection at plug may also result in miss condition. Check for carbon deposits inside spark plug boot.
- If carbon tracking is evident, replace coil and ensure plug wires relating to that coil are clean and tight. Excessive wire resistance or faulty connections may have damaged coil.
- If no-spark condition follows suspected coil, that coil is faulty. Otherwise, ignition control module is cause of no spark. This test may also be performed by substituting a known-good coil for one causing no-spark condition.