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Ignition Checks: Notes

NOTE: To identify ignition system type by application, see ENGINE/VIN ID article.
NOTE: For circuit identification, see appropriate wiring diagram in WIRING DIAGRAMS article.
NOTE: If an ignition failure occurs, ignition system may operate with limited ability using Failure Mode Effects Management (FMEM) or Hardware Limited Operation Strategy (HLOS). When this occurs, trouble codes should be present in PCM memory, engine may be hard to start, and timing will not change.
NOTE: If vehicle does not start, go to CIRCUIT TEST A in TESTS W/CODES - EEC article.

  1. Initial Inspection

    Visually inspect ignition system components and wiring for damage or loose connections. Check condition of spark plugs, spark plug wires, distributor cap and rotor. Repair or replace as necessary.
  2. Ensure idle speed and ignition timing are correct. Check condition of timing belt. A worn or loose belt can cause engine noise and erratic ignition timing.
  3. Ensure spark plug wires are routed in correct firing order. Firing order is 1-2-3-4-5-6. See SPECIFICATIONS article for further information.

  4. Check For Spark

    Disconnect a spark plug wire from spark plug. Connect a Spark Tester (D81P-6666-A) between spark plug wire and ground. Crank engine and check for a strong consistent spark. Repeat test for each spark plug wire. If no spark is present, go to next step. If spark is inconsistent, check distributor cap, rotor and spark plug wires. If spark is okay, ignition system is okay.
  5. Remove high tension coil lead from distributor cap. Connect a Spark Tester (D81P-6666-A) between coil wire and ground. Check spark while cranking engine. If no spark is present, go to next step. If spark is consistent, check distributor cap and rotor.
  6. Ensure distributor rotor turns while cranking engine. Repair as necessary. Using a DVOM, check resistance of coil high tension wire. Coil high tension wire resistance should be 4000-7000 ohms per foot. Replace as necessary. If resistance is okay, go to next step.

  7. Check Coil

    Ensure ignition coil is disconnected. Using a DVOM, measure resistance of ignition coil between primary wire terminals. Measure resistance between ignition coil secondary terminal and positive primary terminal. See appropriate IGNITION COIL RESISTANCE table for specification. If readings are not within specification, replace ignition coil. If ignition coil resistance is okay, go to CIRCUIT TEST JA in TESTS W/CODES - EEC article.
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