Fuel System Test
- Remove the cap from the pressure test port located in the fuel rail. See Fig 1
. Connect Fuel Pressure Gauge (J-34730-1) to the pressure fitting.
- Start vehicle. Pressure should be approximately 31 psi (2.1 kg/cm2
) with the vacuum hose connected to the pressure regulator and 39 psi (2.6 kg/cm2
) with the vacuum hose removed from the pressure regulator.
- Check the fuel pump flow rate. A good fuel pump will deliver at least one liter of fuel per minute with the fuel return line pinched off. If the fuel pump does not pump adequately, inspect the fuel system for a plugged fuel filter or filter sock.
Courtesy of AMERICAN MOTORS/JEEP CORP.
- Fuel pump flow rate can be checked by connecting one end of an old A/C gauge hose to the fuel test port on the fuel rail and inserting the other end of the hose into a container of at least one liter or more capacity.
- Run the fuel pump by installing a jumper wire into diagnostic connector terminals D1-5 and D1-6. Be sure to pinch off the fuel return line or most of the fuel will be returned to the fuel tank.