Evaporative Emissions System: Testing and Inspection

SYSTEM INSPECTION

Fig. 160 System Check:

NOTE: Check condition of wiring harness and/or vacuum lines and connectors before checking sensors or switches.

1. Warm engine to operating temperature.
2. Run at idle.
3. Disconnect vacuum hose from solenoid valve and verify that no vacuum is felt at valve.
4. If not as specified, check valve.

CHARCOAL CANISTER
^ Visually inspect canister for signs of damage or cracks. Replace canister if necessary.

FUEL VAPOR VALVE

Fig. 161 Fuel Vapor Valve:

1. Blow through valve and verify that air flows in direction shown.

Fig. 162 Fuel Vapor Test:

3. Turn valve over and blow. Verify that no air flows.
4. Replace valve if not as specified.


PURGE CONTROL SOLENOID VALVE

1. Disconnect vacuum hoses from valve.
2. Verify that no air can pass through valve.

Fig. 118 Solenoid Valve Test:

3. Unplug valve connector and connect 12V and a ground to valve terminals.
4. Verify that air can pass through.
5. If not as specified, replace valve.

TWO-WAY CHECK VALVE

Fig. 152 Two-Way Valve:

1. Remove valve.
2. Check valve operation with a vacuum pump.
3. Apply approximately 37 mmHg (1.46 inHg) of vacuum at port "A." Verify that air flows through.
4. Apply approximately 44 mmHg (1.73 inHg) of vacuum at port "B." Verify that air flows through.
5. Replace valve if not as specified.