Fuel Pump Volume Test

NOTE: This test is written specifically for Chrysler's Diagnostic Readout Box (DRB-III(R)) scan tool. A generic scan tool may not be capable of performing all necessary test functions.

NOTE: Perform FUEL PUMP PRESSURE TEST before performing FUEL PUMP VOLUME TEST. Perform FUEL PUMP VOLUME TEST in conjunction with FUEL PRESSURE LEAKDOWN TEST . After each repair procedure has been completed, reconnect all components.

Release fuel system pressure. See FUEL PRESSURE RELEASE . Remove air cleaner housing (if necessary) to access quick-connect fuel fittings. Disconnect fuel supply line quick-connect fittings at fuel rail. Connect Fuel Line Pressure Test Adapter 6539) for 5/16" fuel lines, or Fuel Line Pressure Test Adapter (6631) for 3/8" fuel lines, to the disconnected fuel supply line.

NOTE: DO NOT operate fuel pump for longer than 7 seconds, fuel pump reservoir may run empty.

Insert other end of fuel line pressure test adapter into a graduated container. Remove fuel filler cap. Using DRB-III(R) DRB-III(R), actuate fuel pump relay. This should activate fuel pump and pressurize system. Fuel pump should deliver at least .5 pt. (.25 L) of fuel in 7 seconds. If capacity is lower than specification, but fuel pump can be heard through fuel filler, check for a kinked or damaged fuel supply line between fuel rail and fuel pump module. Go to next step.
If fuel supply line is not kinked or damaged and fuel pressure is okay, but capacity is low, replace fuel filter/fuel pressure regulator. Fuel pressure regulator can be replaced separately on some models. If both fuel capacity and pressure are low, replace fuel pump module assembly. See FUEL PUMP MODULE under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - DAKOTA & DURANGO article.