Testing for Spark at Coil

Warning: Apply parking brake and/or block the wheels before performing any test with the engine running.

CAUTION: Spark plug cables may be damaged if this test is performed with more than 1/4 inch clearance between the cable and engine ground.

Spark Check Procedure:

1. Remove the coil secondary cable from the distributor cap.

2. Hold the end of cable about 6 mm 1/4 inch away from a good engine ground.

3. Crank the engine and inspect for spark at the coil secondary cable.

- If spark is not consistant or there is no spark, proceed to the failure to start test.

- If the spark is consistant, continue with this test procedure.

4. Have a helper continue to crank engine and, while slowly moving coil secondary cable away from ground, look for arcing at the coil tower.

- If arcing occurs at the tower, replace the coil.

- If a constant spark is present and no arcing occurs at the coil tower, the ignition system is producing the necessary high secondary voltage. Check the following;

a. Make sure that the spark plugs are firing.
b. Inspect the distributor rotor, cap, spark plug cables, and spark plugs.
c. If they are in proper working order, the ignition system is not the reason why the engine will not start. Inspect the fuel system and engine for proper operation.