Fuel Pressure: Testing and Inspection

1. Connect suitable pressure gauge inline between cold start valve and supply hose or to main fuel supply hose, ensuring that gauge is properly installed to prevent fuel leaks. Nominal fuel pressure with engine running should be 3.0 bar (43 psi).
2. Disconnect and plug vacuum hose to pressure regulator, start engine and observe pressure gauge. Reading with hose disconnected should be approximately 3.3 bar (47 psi).
3. Reconnect vacuum hose to regulator and observe pressure gauge. Reading should drop to approximately 2.8 bar (40 psi).
4. Accelerate engine several times while observing gauge. Pressure reading should rise briefly as engine is accelerated.
5. If reading obtained in step 2 is too low, briefly pinch off return hose from regulator while observing gauge.
6. If pressure reading rises with hose pinched, pump, tank and lines are satisfactory.
7. If pressure readings observed in steps 2 and 3 are not as specified and pump, tank and lines are satisfactory, or if regulator fails to alter pressure in response to engine vacuum, regulator should be replaced.