Description & Operation: CEC/EGR
When ignition is "ON" idle stop solenoid energizes, extending plunger to contact throttle lever. This maintains wider throttle settings at idle to compensate for retarded spark condition produced by this system. Ignition circuit is completed (grounded) through CEC solenoid and cold terminal of temperature switch. At the same time, circuit from ignition switch through time relay coil to ground is completed. With either one or both circuits complete, CEC solenoid is energized, permitting vacuum advance and controlled deceleration by idle stop solenoid. In low gear, after 20 seconds (with engine temperature above 93°F) both time relay and thermostatic coolant temperature switches are open. CEC solenoid is de-energized, vacuum advance is blocked (vented to atmosphere preventing distributor from locking in advance position) and throttle is controlled by idle stop solenoid. With transmission in high gear, transmission switch is closed, grounding circuit from ignition switch. Vacuum advance is restored and CEC solenoid plunger extends, contacting throttle lever to provide deceleration control at a preset value. When ignition is turned "OFF", idle stop solenoid allows throttle valve to close beyond idle, preventing engine dieseling. EGR system vacuum actuated valve controls exhaust gases into intake manifold and is regulated by spark port vacuum signal. At idle there is no EGR. At speed, EGR will be present, depending on throttle opening.