Fuel Pressure: Testing and Inspection

FUEL PUMP PRESSURE TEST-4.0L ENGINE

NOTE: The fuel pressure test port is used on certain engines only. If equipped, the test port will be located on the fuel rail. A sealing cap is screwed onto the test port.

Fuel Pressure Test Port - 4.0L:

All fuel systems are equipped with a fuel tank module mounted, fuel pressure regulator. The fuel pressure regulator is not controlled by engine vacuum.

With engine at idle speed, system fuel pressure should be 338 kPa ± 14 kPa (49.0 psi ± 2 psi).


WARNING: DO NOT ALLOW FUEL TO SPILL ONTO THE ENGINE INTAKE OR EXHAUST MANIFOLDS. PLACE SHOP TOWELS UNDER AND AROUND THE PRESSURE PORT TO ABSORB FUEL.

WARNING: WEAR PROPER EYE PROTECTION WHEN TESTING FUEL SYSTEM PRESSURE.

1. Remove the protective cap at the fuel rail test port. Connect the 0-414 kPa (0-60 psi) fuel pressure gauge (from gauge set 5069) to the test port pressure fitting on the fuel rail.

2. Start the engine and note pressure gauge reading. Fuel pressure should be 338 kPa ± 14 kPa (49.0 psi ± 2 psi) at idle.

3. If pressure is at 0 psi, connect DRB scan tool.

4. If operating pressure is above 51.0 psi, fuel pump is OK but pressure regulator is defective. Regulator is not serviced separately. Replace fuel pump module assembly.