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.

Fig. 171 Testing the purge control valve:

PURGE CONTROL VALVE

1. Remove the purge control valve.
2. Connect a hand vacuum pump to the vacuum nipple of the PCV, Fig. 171.
3. Apply a vacuum of 53 kPa (15 in. Hg) and verify that the vacuum control diaphragm chamber is air tight.
4. Verify that with no vacuum applied air does not pass through the valve and that with 27 kPa (8 in. Hg) air does pass through the valve.

Fig. 172 Testing the purge control valve:

5. Connect a hand vacuum pump to the positive pressure nipple of the purge control valve, Fig. 172.
6. Apply 53 kPa (15 psi) and verify that the valve is leak tight.