Fuel Pump: Testing and Inspection

QUICK TEST:

Remove fuel filler cap and turn ignition On. Then fuel pump operating sound should be heard from fuel filler for about three seconds, then stop. On Sidekick and Samurai, fuel pressure should be felt in the fuel return hose for about three seconds. On all models, if result are not as as specified, refer to the appropriate fuel injection section for diagnosis.

FUEL PRESSURE TEST:

1. Relieve fuel pressure as previously described.
2. Raise vehicle.

Fig. 1 Fuel Pressure Gauge Connections:

3. Remove plug bolt on fuel filter inner union bolt and connect fuel pressure gauge set, 09912--58412, or equivalent, Fig. 1. A small amount of fuel may be released when plug bolt is removed. Cover bolt hole with shop cloth to absorb released fuel.
4. Ensure battery voltage is above 11 volts.
5. On Sidekick, turn ignition On to operate fuel pump, then after three seconds turn it Off. Repeat 3--4 times and inspect fuel pressure.

Fig. 2 Fuel Pump Jumper Connections:

6. On Samurai, connect pink/black and black/white wire terminals with jumper wire, then turn ignition On to operate fuel pump, Fig. 2.
7. On all models, measure fuel pressure under the following conditions: a. With fuel pump operating and engine stopped, fuel pressure should be 34.1--39.8 psi.
b. One minute after fuel pump stops operating, fuel pressure should be above 21.3 psi.
c. On Sidekick, start engine and allow it to warm to normal operating temperature. While engine is idling, fuel pressure should be 29--37 psi.
d. On Samurai, disconnect jumper wire from fuel pump relay. Start engine and allow it to warm to normal operating temperature. While engine is idling, fuel pressure should be 24.2--29.9 psi.