Evaporative Emissions System: Testing and Inspection

Fig. 155 Canister Test:

CHARCOAL CANISTER
1. Blow air into port "A".
Air should not leak.
2. Blow air into both "B" ports.
Air should not leak.
Replace canister if it fails above tests.

Fig. 102 Fuel Check Valve:

FUEL CHECK VALVE
1. Blow air into the port on the fuel tank side.
Some air should pass through to the other port with considerable resistance.
2. Blow air into the port on the canister side.
Air should pass through to the other port with very little resistance.
Replace valve if it fails above tests.

Fuel Tank Vacuum Relief Valve:

FUEL TANK VACUUM RELIEF VALVE
1. Wipe valve housing clean.
2. Draw air through the tank side of the cap.
The valve should click, allowing air to pass through it.
Replace fuel cap if it fails above tests.