Ignition System: Description and Operation

This system provides electronically controlled spark advance and eliminates the need for mechanical and vacuum advance controls in the distributor. The Single Module Engine Controller (SMEC) uses the signals from various sensors to provide optimum driveability under all operating conditions by advancing or retarding the ignition timing.
Under cranking and starting conditions, the SMEC provides a set amount of advanced timing to ensure a quick and efficient start. The amount of electronic spark advance provided by the SMEC is determined by coolant temperature, engine RPM and available manifold vacuum.
The oxygen sensor also sends signals to the SMEC which electronically adjusts the air/fuel mixture to provide the most efficient fuel burn possible.