Spark Plug: Testing and Inspection

SPARK PLUG TEST
1. Remove the spark plug from the engine and connect it to the spark plug cable boot.
2. Ground the spark plug outer electrode (body), and crank the engine. Check for spark across the electrodes.
3. Remove the spark plug from the boot and visually inspect it for cracks in its insulation.
4. Replace the spark plug if it has a weak spark and/or detective insulation.




SPARK PLUG CABLE RESISTANCE CHECK
Measure the resistance of the all spark plug leads.
1. Check cap and coating for cracks.
2. Measure resistance.
Limit: max. 22 k Ohms