Chart A-7B, Fuel System Diagnosis (Fuel Pressure Check): Notes

When ignition is turned on, ECM energizes fuel pump relay for 3 seconds, allowing fuel pump operation. If engine is being cranked or is running, fuel pump will continue to operate as long as ECM is receiving ignition reference pulses. If ignition reference pulses are not detected, fuel pump will stop after 3 seconds.

Fuel pump delivers fuel through fuel filter to fuel injector and fuel pressure regulator, where system pressure is controlled at 34-41 psi (234.4-282.7 kPa). Excess fuel returns to fuel tank through fuel return pipe.

1. Checks if fuel pressure is within specification.
2. Checks fuel feed pipe and hose for leaks.
3. Checks for faulty fuel pump and faulty fuel pressure regulator.
4. Checks for leaky fuel injector, throttle body or for a faulty fuel pressure regulator.
5. Checks for leaks at fuel pump hose connections, faulty fuel pump or a faulty fuel pressure regulator.
6. Checks for restricted fuel feed pipe, faulty fuel filter or restricted fuel return pipe.