MOTORCRAFT DURA-Spark II Ignition Systems: Operation: Notes
The Dura-Spark II systems contain a distributor, electronic control module and ignition coil and function much the same as other solid state systems. See Figs. 1 and 2. An armature on the distributor shaft rotates past a stator (pick-up coil).
Fig 2: Dura Spark II System with Dual Mode Timing Electronic Control Module (Used on Some Fuel Economy and Altitude Package Models)
The armature has the same number of teeth as the engine has cylinders. As the teeth rotate past the pick-up coil, a signal is sent to the electronic control module.
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, which is routed to the spark plugs through the rotor, distributor cap and spark plug wires. System components include the following: