Ignition System: Description and Operation

Fig. 1 Ignition system circuit schematic. 1985 models:

Fig. 2 Ignition system circuit schematic. 1986 - 88 models w/integral ignition coil.:

The principle components of this solid state ignition system are the spark plugs, ignition coil and distributor assembly. The distributor incorporates a rotor, module, pole piece, ignition coil on 1986 - 88 models, vacuum advance and centrifugal advance.
The signal generator (pickup coil), Figs. 1 and 2, is used to generate the ignition signal and consists of a signal rotor (pole piece) and a magnet. The pole piece is attached to the distributor shaft. The magnet and pickup coil are attached to the pickup coil base plate.
When the distributor shaft rotates, the magnetic flux passing through the pickup coil varies due to the change in air gap between the pickup coil and the pole piece. As a result, alternating current is induced in the pickup coil. The voltage induced, switches ON and OFF the module assembly which switches OFF the ignition coil primary current. High voltage is induced within the secondary winding of the ignition coil and ignition sparks are generated at the spark plugs.