Spark Control System: Description

Ignition control system is designed to reduce emissions throughout all engine operating ranges by controlling ignition timing. System consists of a vacuum advance control unit, distributor, thermo vacuum valve (On fuel injected models), sub-advance control solenoid valve (On Federal 2WD and Calif. carbureted models), restrictive orifice (On fuel injected models), check valve (Turbo models) and vacuum lines. The thermo vacuum valve also operates canister purge system.

A dual-diaphragm (main and sub-advancer) type vacuum controller is used on Federal 2WD and Calif. carbureted models, and Fuel Injected non-Turbo models. A single diaphragm (advancer) type vacuum controller is used on Federal 4WD and Fuel Injected Turbo models.