1977-79 Courier

The function of the ventilation system is to divert blow-by vapors into the intake manifold to be burned by the engine. The system consists of a positive crankcase ventilation valve and an oil separator. Ventilating air is routed into the rocker cover from the air cleaner.

The air then is routed to the oil separator, and then to the ventilation valve. The valve meters air to the intake manifold. During idle, when manifold vacuum is high, the valve is pulled closed, limiting air flow to the intake manifold. During normal operation, the valve is open and allows a full flow of ventilating air to flow into the intake manifold.