Fuel Tank Switching Valve: Testing and Inspection

If a complaint involves fuel tank flooding or fuel transfering to or from one tank to the other, check the following:

Before proceding with testing:

- Remove air cleaner assembly
- Remove spare tire and floor board covering fuel pump
- Open both fuel filler caps

Fuel Supply Delivery:

Preliminary Setup
1. Wedge airflow meter flap open slightly.
2. Select right fuel tank with fuel tank switch. Switch button should be in OUT position and there should be an "R" visible on the side of switch button.
3. Turn ignition switch to "ON", but Do not start engine. Fuel pump should now run.


Fuel Return Valves

Note: Fuel tanks should NOT be full to top; fuel pump should be running as outlined in steps 1-3 above.

1. Select right tank.
2. Inside right filler neck, use a long wooden dowel, or equivalent, to hold spring loaded flap open.
3. Using a flashlight, look into fuel filler neck. The end of fuel return line is visible and should have fuel flowing from it. If no flow, check right tank return valve electrical connections:

White/purple wire Battery Voltage
Black wire Ground

4. Check inside left filler neck as above #2. If fuel is flowing, check left return valve for dirt or malfunction.
5. Select left tank.
6. Check left filler neck for fuel flow from return line. If not flowing, check left return valve for battery voltage. Should be no voltage. If voltage, check tank switch.
7. Check right return line for flow. If flowing, check right return valve for battery voltage. Should be none. If voltage, check tank switch. If flowing but no voltage, check valve for dirt.