MOTORCRAFT DURA-Spark II Ignition System: Operation: Notes

As the engine cranks, the distributor shaft turns. A reluctor (armature) on the distributor shaft rotates past a pick-up coil (stator).

The reluctor has the same number of teeth as the engine has cylinders. As the teeth rotate past the pickup coil, a signal is sent to the electronic control module.

Based on this signal, the module then determines when to turn current off and on in the primary windings of the ignition coil. This current collapse in the primary, causes a high voltage surge in the secondary.

This high voltage is routed to the spark plugs through the rotor, distributor cap and spark plug wires. A discussion of system components follows.