Prizm L4-108 1.8L DOHC VIN 8 MFI (1995)
Positive Crankcase Ventilation Valve: Testing and Inspection
FUNCTIONAL CHECK OF PCV VALVE
If an engine is idling rough, check for a clogged Positive Crankcase Ventilation (PCV) valve or plugged hose using the following procedure:
1. Remove PCV hose from valve cover.
2. Run the engine at idle.
3. Place your thumb over end of hose to check for vacuum. If there is no vacuum at hose, check for plugged hoses or manifold port. Replace plugged
or deteriorated hoses.
4. Turn the ignition switch to "LOCK" and remove the PCV hose. Inspect metered orifice for being restricted or plugged. If restricted, clean orifice.
EXCESSIVE BLOW-BY
With this system, any blow-by in excess of the system capacity (from a badly-worn engine, sustained heavy load, etc.) is exhausted into the air
cleaner and is drawn into the engine.
SYSTEM OPERATING REQUIREMENTS
Proper operation of the PCV system is dependent upon a sealed engine. If oil sludging or dilution is noted, and the PCV system is functioning
properly, check engine for possible cause and correct to ensure that the system will function as intended.
