Fuel Selector Valve - Diagnosis/Replacement

83ford6 Article No. 83-23-20

FUEL SYSTEM - (6.9L DIESEL) - FUEL SELECTOR VALVE


LIGHT TRUCKS 1983/84 ECONOLINE & F SERIES






Testing of warranty returned fuel selector valves used on 1983/84 Econoline and F Series with 6.9L diesel engines indicates that some selector valves are being replaced unnecessarily. The following procedure should be followed when a selector valve concern is suspected. Use of this procedure will eliminate unnecessary selector valve replacements.

Figure 17:

Figure 18:

The 6-port diesel fuel valve is powered by a small electric motor which opens and closes the valve ports. The supply and return ports for either tank open and close simultaneously. The valve is shifted to the front mode
(that is the front supply and return ports open to the engine supply and engine return port respectively) by applying a positive 12 volts to terminal number 2 and ground to terminal number 1 (Figures 17 and 18). When the valve reaches the front mode position, and internal switch opens the circuit and stops the motor. Returning the valve to the rear mode is accomplished by reversing power: positive 12 volts to terminal number 1 and ground to terminal number 2. Terminals 3 and 5 connect to the front and rear fuel tank senders, respectively and terminal 4 feeds the fuel gauge. In the front tank mode and internal switch connects terminal 3 to terminal 4 thus supplying the front tank sender signal to the fuel gauge. Terminals 3 and 5 are connected in the rear tank mode. Therefore, a change in the fuel gauge reading (assuming at lease 1/4 tank fuel level difference), is a positive indication that the valve has shifted. For the following diagnostic procedures, both tanks must contain some usable fuel.
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WARRANTY STATUS: "INFORMATION ONLY"