Fuel Pump: Testing and Inspection
Fuel Tank Assembly:
Fuel Pump:
FUEL PUMP ELECTRICAL CHECK
1. Turn ignition "ON" and listen for fuel pump.
^ Fuel pump should run for approx. 5 seconds when ignition is turned "ON" (should be audible, but you may need a second person listening at the fuel filler with the filler cap removed, to tell if the pump is operating).
If OK, go to FUEL PUMP PRESSURE AND CHECK VALVE TEST (below).
If not OK, check fuel pump relay and fuse #13.
Fuel Pump Relay Socket Terminal ID:
2. Remove fuel pump relay and connect jumper wire between receptacle terminals #48 and #52.
^ Fuel pump should run (should be audible, but you may need a second person listening at the fuel filler with the filler cap removed, to tell if the pump is operating).
If not, disconnect electrical connector at the tank and repeat step 3 while monitoring voltage between terminals #1 (G/Y wire) and #4 (Brn wire).
^ Should have battery voltage while jumper wire is connected. If voltage is OK and pump does not run, replace pump. If no voltage is present, check for open or short to ground in wiring between fuel pump relay terminal #52 and fuse #13, or between fuse #13 and fuel pump.
FUEL PUMP PRESSURE AND CHECK VALVE TEST
Connecting Pressure Gauge For Fuel Pump Check:
1. Disconnect fuel inlet hose from fuel filter and connect to fuel pressure gauge as shown in illustration (shut-off valve in closed position).
2. Operate fuel pump for about 15 seconds then turn pump "OFF". (Operate pump by bridging terminals of fuel pump relay socket as in step 2 of electrical test above.)
3. Wait 10 minutes then observe residual pressure on gauge.
^ Should be 51 psi (3.5 bar) minimum.
If pressure drops below the specification and there are no leaks, replace fuel pump check valve.
FUEL PUMP VOLUME TEST
1. Reconnect fuel supply line to fuel filter (line must be connected because this test checks for adequate volume under normal pressure).
Fuel Return Line Connection:
2. Disconnect fuel return line at connector next to fuel filter (see illustration), and direct outlet from fuel distributor into suitable measuring container. You may need to add an extra piece of hose to do this safely.
3. Remove fuel filler cap.
4. Connect voltmeter between terminals of fuel pump harness connector with pump connected.
5. Energize fuel pump for 30 seconds (see step 2 of electrical test above) and note operating voltage at the pump.
Fuel Pump Volume Vs. Supply Voltage:
6. Check volume of fuel in container after 30 seconds of operation and compare with chart.
^ If volume is less than that specified for the noted operating voltage, check for restricted or plugged fuel filter and supply line. If filter and line are OK, replace fuel pump.