Vacuum Advance Solenoid

This electrically operated 2-position plunger control valve serves as a on/off vacuum supply switch to distributor vacuum advance unit. When de-energized, spring loaded plunger seats against vacuum inlet and opens distributor advance unit to atmospheric vent. When energized, plunger opens vacuum port from carburetor to advance unit. In opening vacuum port, plunger also closes atmospheric vent. Vent to atmosphere is provided to prevent advance unit from becoming locked in an advanced position.