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. Release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE .

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. Fuel pressure specification is 53-63 psi (366-434 kPa). Using Hose Clamp Pliers (C4390), pinch the rubber fuel line between the fuel pressure gauge and the engine. 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, replace the fuel pump module. If no, go on to next step.

Remove Hose Clamp Pliers. Start the engine and allow the fuel system to reach maximum pressure. Turn the ignition off. Fuel specification is 53-63 psi (366-434 kPa). Install Hose Clamp Pliers between the fuel pressure gauge and fuel pump module. 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 drop? If yes, replace the leaking fuel injectors. If no, the test is complete.