Checking Fuel Pressure Leak Down: Testing

WARNING: The fuel system is under a constant pressure even with the engine off. Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. To release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE .

Install a fuel pressure gauge. Start the engine and observe the fuel pressure reading. Fuel pressure specification is 53-63 psi (366-434 kPa). Turn the ignition off. Monitor the fuel pressure gauge for a minimum of 5 minutes. The pressure should not fall below 35 psi (241 kPa). Does the fuel pressure gauge fall below the above specification? If yes, go on to next step. If no, the fuel system is working normally.

Before continuing visually and physically inspect the fuel delivery system for external leaks or damage. Repair/replace as necessary. Turn the ignition off. Install special 5/16" Fuel Line Adapter (6539). Attach a fuel pressure test gauge to the T-fitting on the Fuel Line Adapter. Start the engine and allow the fuel system to reach maximum pressure. Turn the ignition off. The pressure should not fall below 35 psi (241 kPa). Does the fuel pressure gauge fall below the above specification? If yes, check the Fuel Delivery System between the fuel gauge and the fuel pump module. Inspect the seal points and the fuel lines for signs of fuel leakage. Repair as necessary. If OK, replace the Fuel Pump Module. If not OK, repair fuel system as necessary.