Ignition System: Description and Operation

PURPOSE
The Distributor Ignition (DI) system controls fuel combustion by providing a spark to ignite the compressed air/fuel mixture at the correct time. To provide improved engine performance, fuel economy, and control of exhaust emissions.

OPERATION AND CONSTRUCTION
The DI system consists of the battery, distributor, ignition switch, spark plugs, and the primary and secondary wiring. It is part of the computerized engine control system. The Powertrain Control Module (PCM) monitors information from various engine sensors, computes the desired spark timing, and signals the Ignition Control Module (ICM) to change engine timing.