Fuel Pressure: Testing and Inspection

Checking Fuel System Pressure:

1. Relieve fuel system pressure.
2. Using an extra piece of fuel injection hose, connect fuel pressure gauge as shown in illustration.

Energizing Fuel Pump At Diagnostic Connector:

3. Energize fuel pump by bridging "Fp" and "GND" terminals of diagnostic test connector and turning ignition "ON" .
4. Pinch off hose between gauge and pulsation damper with a clamp.

5. Observe fuel pressure on gauge (maximum pump pressure).

64 - 85 psi (441 - 589 kPa)

^ If pressure is higher than maximum specified, replace fuel pump.
^ If pressure is lower than minimum specified, check fuel filter. If filter is OK, replace pump.

6. Remove pinch clamp from hose between gauge and pulsation damper.
7. Start engine and let idle.

8. Observe fuel pressure on gauge (system operating pressure).

30 - 37 psi (206 - 255 kPa)

^ If pressure is higher than maximum specified, check fuel return line for kinks or restriction.
^ If pressure is lower than minimum specified, check fuel filter.
^ If filter and return line are OK and pressure is still not within specified range, replace pressure regulator.

9. Disconnect vacuum hose from fuel pressure regulator with engine idling. Fuel pressure should increase when vacuum hose is removed. If not, replace pressure regulator.

38 - 46 psi (265 - 314 kPa)

10. Shut engine "OFF" and wait 5 minutes.Observe residual pressure on gauge.

Minimum 21 psi (147 kPa)

11. If not, check for leaking fuel injector(s). If injectors are not leaking, replace pressure regulator.
12. If all test results are OK, fuel pump and pressure regulator are OK.