Canister Purge Solenoid: Description and Operation

Some 1981-82 vehicles equipped with Computer Command Control C-3, use a solenoid to control the vacuum to the purge valve. When the system is in "Open Loop" operation, the ECM energizes the solenoid valve, blocking vacuum to the purge valve. When the System switches to "Closed Loop", the solenoid is de-energized and vacuum is supplied to the purge valve. Fuel vapors stored in the vapor canister are then directed to the induction system, where they are burned.