Evaporative Emissions System: Testing and Inspection

Fig. 151 Evaporative System Check:

SYSTEM INSPECTION

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

1. Warm engine tooperating temperature.
2. Run at idle.
3. Disconnect vacuum hose (White) from solenoid valve and verify 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 if necessary.

CHECK AND CUT VALVE

Fig. 84 Separator:

1. Remove valve.
2. Connect pressure gauge to passage from fuel tank.

Check And Cut Valve Testing:

3. Blow through valve from "A", and check that it opens at pressure of 0.78 - 1.00 psi (5.39 - 6.87 kPa, 0.055 - 0.07 kg/sq cm).
4. Remove gauge and connect to passage to atmosphere.
5. Blow through valve from "B" and check that it opens at pressure of 0.14 - 0.71 psi (0.98 - 4.9 kPa, 0.01 - 0.05 kg/sq cm).

NOTE: Perform test with valve held horizontally. Otherwise, check balls in valve will close passages.

FUEL VAPOR SEPARATOR

Fuel Vapor Separator:

1. Locate separator in rear wheel well.
2. Remove separator.
3. Visually check separator for signs of damage.
4. Replace if necessary.

PURGE CONTROL SOLENOID VALVE

Fig. 146 Solenoid Test:

1. Disconnect vacuum hoses from valve.
2. Verify that no air can pass through valve.
3. Disconnect valve connector and connect 12V and a ground across 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 1.46 inHg (37 mmHg) vacuum at port "A" verify that air flows through valve.
4. Apply approximately 1.73 in.Hg (44 mmHg) vacuum at port "B" verify that air flows through the valve.
5. Replace valve if not as specified.