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Fuel Selector Valve Ford Bronco II I

Testing & Diagnostics 3 illustrations ~2574 words

COMPONENT TESTING

Note. Specific component testing information not available. Refer to any tests performed during REMOVAL & INSTALLATION or OVERHAUL procedures

DESCRIPTION

Systems usually consist of a fuel selector valve, fuel pump cut-off relay, tank selector valve or relay, inertia switch, selector switch and an electric fuel pump.

A 3-port electrically actuated fuel tank selector valve is used on Ford 150 and 350 series models. Other Ford models use a 6-port selector valve. (Scheme 84)

Scheme 84

Scheme 84: DESCRIPTION
Scheme 84: DESCRIPTION

OPERATION

The electrically-actuated fuel selector valve is spring-loaded. In de-energized state, fuel pump is fed from rear tank. When activated by selector switch, fuel feed transfers from rear to front tank.

FUEL DOES NOT SWITCH TANKS 3-PORT FUEL VALVE

  1. Turn ignition switch to "RUN" and fuel tank selector switch to "FRONT" position. Disconnect valve wire connector. Using a test light, check for voltage between wire harness terminal and ground. If voltage is not present, check fuse. If fuse is bad, repair short circuit. If fuse is okay, check switch for continuity in auxiliary tank position. Repair and replace as necessary. If voltage is present, go to next step.
  2. Reconnect valve wire connector. Place a steel paper clip on bottom end of valve. Magnetic action should hold paper clip to valve end plate. If clip holds, remove clip and go to next step. If clip does not hold, ground valve case to frame rail with jumper wire and repeat check. If clip holds, remove valve mounting bolts and clean mounting area. Reinstall valve using cadmium or zinc-plated bolts and washers. If clip does not hold, replace valve and solenoid assembly.
  3. Position fuel tank selector switch to "MAIN" position and pinch-off fuel hose from valve to main tank. Remove fuel line from carburetor and put fuel line into a container. Remove battery feed from coil and crank engine. Check fuel flow. If fuel flow is okay, replace valve and solenoid assembly. If not, go to next step.
  4. Open fuel hose and crank engine for fuel flow. Position fuel tank selector switch to "AUX". Pinch-off fuel hose from valve to auxiliary tank. Crank engine and observe fuel flow. If not okay, check for restricted fuel line. If okay, replace valve and solenoid assembly.

Scheme 85

Scheme 85: FUEL DOES NOT SWITCH TANKS 6-PORT FUEL VALVE (EXCEPT HOT FUEL HANDLING)
Scheme 85: FUEL DOES NOT SWITCH TANKS 6-PORT FUEL VALVE (EXCEPT HOT FUEL HANDLING)
  1. Remove electrical connector from tank selector valve. Turn ignition switch to "RUN" position. Move selector switch to "FRONT" position and check for voltage between connector terminals No. 2 and 1. (Scheme 85) If voltage is not present, check ground. If voltage is still not present, go to step 3). If voltage is present, check voltage between terminal No. 2 and ground. If voltage is present, go to next step. If not, go to step 3).
  2. Using a short piece of wire, jump motor terminal No. 2 to battery positive and motor terminal No. 1 to ground. Motor should run. Reverse jumper wires and motor should run in opposite direction. If motor does not run in both directions, replace. If motor is okay, go to step 4).
  3. Check for voltage across fuse No. 15 in fuse panel. If okay, go to next step, if not, repair short in selector valve circuits.
  4. Remove fuel tank selector switch from harness connector. Position selector switch in "FRONT" position. On diesel models, check for continuity between terminals No. 1 and 2, and 4 and 5. On all other models, check for continuity between terminals No. 2 and 4, and 1 and 3. Position selector switch in "REAR" position. On diesel models, check for continuity between terminals No. 2 and 3, and 5 and 6. On all other models, check for continuity between terminals No. 1 and 4, and 2 and 3. If continuity is not present, replace switch. If continuity is present, on diesel models check continuity of circuits No. 786 (Red) and 789 (Brown/White) between selector switch and selector valve. On all other models, check continuity of circuits No. 974 (Orange) and 674 (Brown/White). If okay, go to next step. If not, repair open circuit.
  5. Turn ignition switch to "RUN" position. Position selector switch to "FRONT" position and turn ignition off. Pinch off fuel supply line from rear tank to selector valve. Remove vacuum purge valve from fuel filter adapter. Install Adapter 3019 from Rotunda Pressure Test Kit (091-00002). Start and allow engine to idle with no load. Open clamp on hose and allow fuel to flow into a container. Fuel flow should be solid and continuous. If okay, remove clamp and go to step 6). If not, go to next step.
  6. Disconnect supply hose to engine at selector valve. Disconnect supply hose from front tank at selector valve. Connect the 2 hoses together and repeat step 5). If okay, replace fuel selector valve. If not, check front fuel tank sender, sediment, fuel filter and fuel lines for kinks or obstructions. Repeat step 5).
  7. Turn ignition to "RUN" position. Position selector switch to "REAR" position and turn ignition off. Pinch-off fuel supply line from front tank to selector valve. Remove vacuum purge valve from fuel filter adapter. Install Adapter 3019 from Rotunda Pressure Test Kit (019-00002). Start engine and allow to idle with no load. Open clamp on hose and allow fuel to flow into a container. Fuel flow should be solid and continuous. If okay, fuel supply system is working properly. Go to step 9). If not, go to next step.
  8. Disconnect supply hose to engine at selector valve. Disconnect supply hose from rear tank at selector valve. Connect the 2 hoses together. Repeat step 5). If okay, replace fuel selector valve. If not, check fuel lines for kinks or obstructions. Repeat step 7).
  9. Disconnect fuel return hose from engine at selector valve. Insert hose into suitable container. Turn ignition switch to "RUN" position and start engine. Fuel flow should be solid and continuous. If not, check fuel lines for kinks or obstructions. If okay, go to next step.
  10. Disconnect fuel return line to problem tank from selector valve. Attach a length of 5/16" diameter hose to selector valve return port and insert line into suitable container. Start engine. Fuel flow should be solid and continuous. If okay, check fuel sender and fuel lines for kinks or obstructions. If not, replace fuel valve.

FUEL DOES NOT SWITCH TANKS 6-PORT FUEL VALVE (WITH HOT FUEL HANDLING)

  1. Turn ignition switch to "ON" position. Position selector switch to "FRONT" mode. Disconnect selector valve connector. Check for voltage between connector terminal No. 2 and ground. If voltage is present, go to step 3).
  2. If no voltage is present, check voltage across fuse at fuse block. If fuse is blown, check selector valve circuit for shorts. Repair shorts, replace fuse and repeat step 1). If fuse is okay, go to step 6).
  3. Check for voltage between selector valve connector terminals No. 2 and 1. If voltage is present, go to step 4). If no voltage is present, check for open ground circuit from valve connector, through selector switch to ground. If circuit is okay, go to step 6). If not okay, repair ground circuit and repeat test.
  4. Place switch in "REAR" position and check for voltage between connector terminal No. 1 and ground. If voltage is present, go to step 5). If no voltage is present, go to step 6).
  5. Check for voltage between selector valve connector terminals No. 2 and 1. If voltage is present, go to step 8). If no voltage is present, check for open ground circuit from valve connector, through selector switch to ground. If circuit is okay, go to step 6). If not okay, repair ground circuit and repeat step 3).
  6. Remove selector switch from instrument panel and disconnect from harness. With switch in "FRONT" position, check for continuity between terminals No. 1 and 2, and between terminals No. 4 and 5.
  7. Place switch in "REAR" position and check for continuity between terminals No. 2 and 3, and between terminals No. 5 and 6. If switch is okay, go to step 10). If switch is not okay, replace switch. NOTE: Selector valve will make a "zip" sound when shifting from one mode to another.
  8. Using a jumper wire, connect selector valve terminal No. 2 to battery positive post. Using a second jumper wire, connect terminal No. 1 to ground. If valve is in "FRONT" mode, nothing will happen. Reverse jumper wires. Valve should shift to "REAR" mode.
  9. Reverse jumper wires once more. Valve should shift to "FRONT" mode. If valve shifts into both modes, go to step 12). If valve does not shift into both modes, replace fuel selector valve.
  10. On "E" series, check continuity of Brown/Orange wire (circuit No. 808) and Red/Yellow wire (circuit No. 739) between selector switch and selector valve. On "F" series, check continuity of Brown/White wire (circuit No. 674) and Orange wire (circuit No. 974) between selector switch and selector valve.
  11. If continuity between selector switch and selector valve is okay, go to step 12). If continuity between selector switch and selector valve is not okay, repair open circuits as necessary.
  12. Remove connector from oil pressure switch and insert temporary shorting wire between 2 connector terminals. Pinch off fuel line between rear tank and selector valve. Remove fuel hose to carburetor and place end of fuel hose into a container. NOTE: Fuel pump volume is about 1/2 gallon per minute.
  13. Turn ignition switch to "RUN" position. Place switch in "FRONT" position. Check for a solid, continuous fuel flow. If fuel flow is not okay, go to step 14). If fuel flow is okay, remove clamping tool from rear supply line and go to step 18).
  14. Disconnect supply hose to engine at selector valve. Disconnect supply hose from front tank at selector valve. Connect 2 hoses together using a length of fuel line. Repeat steps 12) and 13). If fuel flow is okay, replace fuel selector valve.
  15. If fuel flow is not okay, check front fuel tank sender, fuel lines and fuel filter for restrictions. If restrictions are found, clean, repair or replace components as necessary and repeat steps 12) and 13).
  16. If lines, filter and sender are okay, remove front fuel tank sender connector. Connect a 12-volt test light to pump and ground terminals of sender connector.
  17. With ignition switch in "RUN" position and with switch in "FRONT" position, test light should light continuously and should go out as soon as rear tank is selected. Check fuel pump. If fuel pump is okay, continue test.
  18. Remove connector from oil pressure switch and insert temporary shorting wire between 2 connector terminals. Pinch off fuel line between front tank and selector valve. Remove fuel hose to carburetor and place end of fuel hose into a container.
  19. Turn ignition switch to "RUN" position and place switch in "REAR" position. Check for a solid, continuous flow of fuel. If fuel flow is not okay, go to step 20). If fuel flow is okay, selector valve is operating properly.
  20. Disconnect supply hose to engine at selector valve. Disconnect supply hose from rear tank at selector valve. Connect 2 hoses together using a length of fuel line. Repeat steps 18) and 19).
  21. If fuel flow is okay, replace fuel selector valve. If fuel flow is not okay, remove rear fuel tank sender connector. Connect a 12-volt test light to pump and ground terminals of sender connector.
  22. With ignition switch in "RUN" position and mode switch in "REAR" position, test light should light continuously and go out as soon as front tank is selected. Check fuel pump. If fuel pump is okay, fuel supply system is okay.

DOES NOT CHANGE TANKS 6-PORT FUEL VALVE (ALL OTHER MODELS)

  1. Remove cover from in-process starting aid. Ground terminals "97C" and "359J". Remove electrical connector from tank selector valve. Turn ignition switch to "RUN" position. Move selector switch to "FRONT" position. Check for voltage between connector terminals No. 2 and 1. If voltage is not present, go to step 3). If voltage is present, go to next step.
  2. Ground motor terminal No. 2 to battery positive post and motor terminal No. 1 to ground. Motor should run. Reverse leads and motor should run in opposite direction. If it does, go to step 4). If not, replace valve.
  3. Using a test light, check for voltage at output terminal of inertia switch. If okay, go to next step. If not, reset inertia switch or repair wiring as necessary.
  4. Remove fuel tank selector switch knob and trim bezel. Remove switch from harness connector. Position selector switch in "FRONT" position. Check for continuity between terminals No. 1 and 2, and 4 and 5. Position selector in "REAR" position and check continuity between terminals No. 2 and 3, and 5 and 6. If okay, go to next step. If not, replace fuel selector switch.
  5. Check continuity between circuits No. 974 (Orange wire) and 674 (Brown/White wire) between selector switch and selector valve. If okay, go to next step. If not, repair open circuit.
  6. Turn ignition switch to "RUN" position. Position selector switch to "FRONT" position and turn ignition off. Remove fuel supply line from rear tank to selector valve and plug valve port. Remove fuel hose at fuel filter and insert line into container. Turn ignition switch to "RUN" position and get at least one pint of fuel. Ensure there is a continuous flow of fuel. If there is, connect rear supply line to valve and go to step 8). If not, go to next step.
  7. Remove push-on connector to engine at selector valve and front tank at selector valve. Connect 2 hoses together and repeat step 6). If system works, replace fuel selector valve. If not, check all fuel system components for kinks or obstructions. Repeat step 6).
  8. Turn ignition switch to "RUN" position. Position selector switch to "REAR" position and turn ignition off. Remove fuel supply line from front tank to selector valve and plug valve port. Turn ignition switch to "RUN" position and obtain at least one pint of fuel. Ensure fuel flow is solid and continuous. If okay, fuel supply system is okay. Reconnect fuel lines and go to step 10). If not okay, go to next step.
  9. Disconnect push connect to engine at selector valve. Disconnect push connect from rear tank at selector valve. Connect 2 tubes together and repeat step 6). If system is okay, replace fuel selector valve. If not, check rear fuel tank sender and fuel lines for kinks and obstructions.
  10. Disconnect fuel return line push connect from engine at selector valve. Insert line into container to catch fuel. Turn key to "RUN" position. Position selector switch to tank with problem. Start engine and ensure there is a continuous solid flow of fuel. If not, check return line for kinks or obstructions and repeat test. If okay, go to next step.
  11. Disconnect fuel return line push connect to problem tank from selector valve. Install a push connect with 5/16" diameter hose to selector valve return port. Insert line into container to catch fuel. Start engine and ensure there is a continuous solid flow of fuel. If not, replace fuel valve. If okay, check fuel sender and fuel line to tank for kinks or obstructions.

Disconnect fuel hoses from selector valve. Remove electrical connections. Remove nut and ground wire. Remove valve attaching bolts and valve. To install, reverse removal procedure. Ensure ground wire is securely fastened. Because solenoid is internally grounded, specified mounting bolts must be used.

SPECIFICATIONS

Note. Specifications table not available. Refer to specifications within appropriate TESTING subject(s) in this article.

Scheme 86

Scheme 86: WIRING DIAGRAMS
Scheme 86: WIRING DIAGRAMS

See also:
• TESTING

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