Chart A2-7B, Fuel System Diagnosis (Fuel Pressure Check): Notes

When ignition switch is in ON or START position, circuit opening relay will be energized to allow fuel pump to operate to pressurize system. Fuel pump will continue to operate if PCM receives an ignition signal when engine is started. Fuel pump operates as long as circuit opening relay is energized by PCM. When circuit opening relay is de-energized, fuel pump will stop operating. Fuel pump delivers fuel to fuel rail where pressure is maintained by fuel pressure regulator at 41 psi (282.7 kPa) more than pressure inside intake manifold. Excess fuel is returned to fuel tank through a return pipe and hoses.

1. Measures fuel pressure with ignition switch in ON position.
2. Determines if fuel pressure is normal.
3. Checks for a leaking fuel pressure regulator.
4. Checks for plugged fuel injectors.
5. Checks for leaking fuel injectors or a leaking fuel pump.
6. Checks for a leaking fuel pressure regulator or fuel pump