Evaporative Emissions System: Testing and Inspection

Fig. 117 Solenoid Valve:

SYSTEM INSPECTION


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

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


CHARCOAL CANISTER

Visually inspect the cannister for signs of damage of cracks. Replace the cannister if necessary.

Fig. 84 Separator:

CHECK AND CUT VALVE

1. Remove the check and cut valve.
2. Connect a pressure gauge to the passage from the fuel tank.

Check And Cut Valve Testing:

3. Blow through the valve from "A", and check to see that it opens at a pressure of 6.38 - 8.34 kPa (0.065 - 0.085 kg/sq cm, 0.92 - 1.2 psi)
4. Remove the pressure gauge, and connect it to the passage to atmosphere.
5. Blow through the valve from "B", and check to see that it opens at a pressure of 0.98 - 4.9 kPa (0.01 - 0.05 kg/sq cm, 0.14 - 0.71 psi).

NOTE: This test should only be performed with the valve held horizontally. Otherwise, the check balls in the valve will close the passages.

Fig. 119 Separator Inspection:

FUEL VAPOR SEPARATOR

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


SOLENOID VALVE (PURGE CONTROL)

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

Fig. 118 Solenoid Valve Test:

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

Fig. 152 Two-Way Valve:

TWO-WAY CHECK VALVE

1. Remove the check valve.
2. Check the operation of the valve with a vacuum pump.
3. Apply approximately 37 mmHg (1.46 in.Hg) of vacuum at port "A" verify that air flows through the valve.
4. Apply approximately 44 mmHg (1.73 in.Hg) of vacuum at port "A" verify that air flows through the valve.
5. Replace the valve if not to specification.