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Fuel System Test

  1. Remove cap from pressure test port located in fuel rail. See Fig 1 . Connect Fuel Pressure Gauge (J-34730-1 ) to pressure fitting.
  2. Start vehicle. Pressure should be approximately 31 psi (2.1 kg/cm2 ) with vacuum hose connected to pressure regulator and approximately 39 psi (2.6 kg/cm2 ) with vacuum hose removed from pressure regulator.
  3. Check fuel pump flow rate. A good fuel pump will deliver at least one liter of fuel per minute with fuel return line pinched off. If fuel pump does not pump adequately, inspect fuel system for a plugged fuel filter or filter sock.
  4. Fuel pump flow rate can be checked by connecting one end of an old A/C gauge hose to fuel test port on fuel rail and inserting other end of hose into a container of at least one liter or more capacity.
  5. Run fuel pump by installing a jumper wire between diagnostic connector terminals D1-5 and D1-6 (located on right wheelwell, behind relay block). See Fig 1 . Be sure to pinch off fuel return line or majority of fuel will be returned to fuel tank.
Fig 1: Fuel Pressure Regulator, Fuel Rail & Fuel Injectors
G113133Courtesy of CHRYSLER MOTORS.