Chart A1-7B, Fuel System Diagnosis (Fuel Pressure Check): Notes

When ignition is turned on, ECM will turn in-tank fuel pump on. Fuel pump will stay on as long as engine is cranking or running and ECM is receiving ignition reference pulses. If no ignition reference pulses are received by ECM, ECM will shut off fuel pump about 2 seconds after ignition is turned on or when engine stops.

Fuel pump will deliver fuel to throttle body and injector, then to fuel pressure regulator, where system pressure is controlled to about 23-31 psi (1.6-2.2 kg/cm² ) with ignition on. With engine at idle and normal operating temperature, fuel pressure will be approximately 13-20 psi (.9-1.4 kg/cm² ). Excess fuel is then returned to fuel tank.

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