Fuel Pressure: Testing and Inspection

FUEL PUMP PRESSURE TEST 3.0L (MPI)

NOTE: Chrysler DOES NOT provide a procedure to test the fuel pressure without the testers and/or tools mentioned.

Fuel Tank Filter And Hose Location:

Fuel Hose To Fuel Rail Connection:

1. Perform fuel system pressure release.
a. loosen gas cap to release any in-tank pressure
b. remove wiring harness connector from injector
c. ground injector terminal with a jumper
d. connect a jumper wire to second terminal and touch battery positive post for no longer than ten (10) seconds
e. remove jumper wires
f. continue fuel system service

2. Disconnect the 5/16 inch fuel supply hose from the engine fuel line assembly.

CAUTION: Use care when removing the fuel hose to prevent damage to the hose or the fuel line. Replace hose if damaged.

Connect fuel system pressure testers C-3292 and C-4749 between fuel supply hose and engine fuel line assembly.

3. Using ATM tester C-4805, with the key in the RUN position depress the ATM button. This will activate the fuel pump and pressurize the system. If the gauge reads 250 kPa ±14kPa (36 psi ±2.0 psi) pressure is correct and no further testing is required.

4. If fuel pressure is below specifications, install tester between fuel supply tube and fuel filter inlet hose.

5. Repeat test. If pressure is now correct, replace fuel filter. If no change is observed, gently squeeze return hose. If pressure increases, replace pressure regulator. If no change is observed, problem is either a plugged fuel pump filter sock or defective fuel pump.

6. If pressure is above specifications, remove fuel return hose from the chassis line at the fuel tank and connect a 3 foot piece of fuel hose to the return line. Put the other end into an approved gasoline container with a minimum 2 gallon capacity. so that fuel will flow into container. Repeat test. If pressure is now correct, check in-tank return hose for kinking. Replace fuel pump assembly if in-tank reservoir check valve or aspirator jet is obstructed. This test should be performed when fuel tank is half full or greater.

Fig. 14 Removing fuel pressure regulator hose:

7. If pressure is still above specifications, remove fuel return hose from fuel return line. Connect a substitute hose to the fuel return line and place the other end of hose into a clean container. Repeat test. If pressure is now correct., check for restricted fuel return line. If no change is observed, replace fuel pressure regulator.