Installing ppe fuel pump on 2001 6.6 chevy

The example below shows a 2002 LB7 engine cranking over with the ignition relay unplugged. Removing the relay also shuts down part of the ECM, so the FRPR does not operate, and the system goes to maximum pressure, or as much pressure as the pump is capable of. This way you know that the fuel that returns during the fuel return test is all leakage, and not normal injector bleed-off.

This shuts down the FICM, so no fuel injectors are energized during cranking. This is a preliminary test to checking the fuel return rates on the following pages. Fuel pressure regulator Cranking High Pressure Test.If the fuel supply side is okay, but the cranking pressure is low and the hand primer is stiff, the following list shows the more likely causes. Testing the high side with a supply side fault will definitely lead to an incorrect diagnosis. If pressure is now okay, you have a fuel supply issue. If the hand pump is soft and then becomes hard, recheck cranking fuel rail pressure.

If the engine wonвЂ™t start and actual fuel rail pressure is low during cranking, the supply side should be checked before testing the high side. On a good fuel system the fuel pump can produce maximum system pressure during cranking. Before starting, it is important to note that the high pressure fuel pump must be able to produce a minimum of 2500 to 3500 psi while cranking during the Cranking High Pressure Test outlined below for the test to be valid.

Installing ppe fuel pump on 2001 6.6 chevy