Evaporative Emissions System: Testing and Inspection

Overfill Limiter (Two Way Valve):

OVERFILL LIMITER VALVE

Remove the overfill limiter valve and blow gently through both ends. Air should pass through the valve in both directions with slight resistance.


PURGE CONTROL VALVE

1. With the engine warmed up to normal operating temperature and ignition key in the "OFF" position, remove the purge hose from the air cleaner and blow into it. Air should not flow through the purge control valve.
2. Start the engine and accelerate it to 2000 rpm. Blow into the hose and verify that air passes through the purge control valve.
3. If air will not pass check the operation of the thermo valve and its connecting vacuum hoses for breaks and obstructions.