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. On models with SOHC engine, remove air cleaner from throttle body and position aside. Disconnect fuel feed hose from throttle body.
3. On models with DOHC engine, remove ISC valve and EGR modulator bracket, if equipped, then disconnect fuel feed hose from fuel delivery pipe.

Fig. 3 Fuel Pressure Gauge Connections:

Fig. 4 Fuel Pressure Gauge Connections:

4. On all models, connect fuel pressure gauge between fuel feed hose and fuel delivery component, Figs. 3 and 4.
5. Install components previously removed.
6. Ensure battery voltage is 11 volts or greater.
7. Remove fuel pump relay from main fuse box after disconnecting its coupler, then connect coupler to relay away from fuse box.
8. To operate fuel pump, connect pink and white/blue wire terminals with a jumper wire, then turn ignition On.
9. Measure fuel pressure under the following conditions:
a. With fuel pump operating and engine stopped, fuel pressure should be 35.5--38.4 psi on DOHC engine models. On SOHC engine models, fuel pressure should be 22.7--29.9 psi.
b. One minute after fuel pump stops operating, fuel pressure should be above 25.6 psi, on DOHC engine models. On SOHC engine models, fuel pressure should be above 12.8 psi.
c. Disconnect service wire. Start engine and allow to warm to normal operating temperature. Inspect fuel pressure while engine is at idle. On DOHC engine models, fuel pressure should be 25.6--29.9 psi. On SOHC engine models, fuel pressure should be 12.8--20.0 psi.