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Ignition Systems - Optical: Operation: Notes

Optical distributor is connected to SMEC system by a lead wire that is plugged into base of distributor. The SMEC determines correct timing of ignition and signals ignition coil to produce an electrical impulse to fire the appropriate spark plug. Amount of electronic spark advance provided by SMEC is determined by 3 input factors, coolant temperature, engine RPM and available manifold vacuum. Distributor mounted optical pick-up assembly triggers onset of fuel injection and establishes base timing point.

Fig 1: Cross Sectional View Of Optical Distributor
G113228Courtesy of CHRYSLER MOTORS.