Download The PCV system is designed to prevent blow-by fuel from escaping to the atmosphere by drawing it directly into the intake manifold. The PCV valve accommodates a spring-loaded plunger which is lifted in proportion to consumption manifold vacuum. Under high vacuum, blow-by is returned on to the manifold via the breather chamber and PCV valve with contemporary air. When consumption manifold vacuum decreases (huge open throttle) and vacuum within the air cleaner will increase, the PCV valve closes and the blow-by is returned via the cylinder head cowl breather hose and into the air cleaner. The PCV valve also acts as a check valve when the engine backfires to stop crankcase explosion. 1: PCV system components-1984-87 1.5L engines.2: PCV system components-1988-ninety one 1.6L engines.3: PCV system parts-1992-ninety five engines.Constructive Crankcase Air flow (PCV) Valve For PCV valve elimination, discuss with Routine Upkeep of this information. 1. Find the PCV valve. With the engine operating at idle, use pliers to pinch the PCV hose between the valve and the intake manifold. It needs to be attainable to listen to the spring loaded valve click on shut.