CRANKSHAFT- 1W5008 - Caterpillar

Introduction
Illustration 1 g06004717
Typical example
(1) Primary fuel filter
(2) Electric transfer pump
(3) Secondary fuel filter
(4) Inlet pressure regulator
(5) Fuel injection pump
(6) Fuel manifold (rail)
(7) Pressure relief valve
(8) Electronic unit injector
(A) Fuel tankFuel is drawn from the fuel tank through a 100 micron primary fuel filter and a water separator.The fuel then flows to an external electric transfer pump. The flow rate of the electric transfer pump is 1.5 L/min to 2.0 L/min (0.4 US gpm to 0.5 US gpm).From the electric transfer pump, fuel flows to the secondary fuel filter.A pressure regulator that is installed in the low-pressure fuel system controls the fuel pressure to the fuel injection pump.Note: There is a separate fuel return line from the pressure regulator to the fuel tank.From the secondary fuel filter, the fuel flows to the fuel injection pump. The fuel is pumped at an increased pressure of 200 MPa (29000 psi) to the fuel manifold (rail).Fuel that has too high a pressure from the fuel manifold (rail) returns through the pressure relief valve to the return line. Fuel that is leak off from the electronic unit injectors flows to the return line. The fuel may then flow through an optional fuel cooler on the way back to the fuel tank.High-Pressure Fuel System
Illustration 2 g03789648
Typical example
(1) Electronic unit injector
(2) Fuel manifold (rail)
(3) Fuel pressure sensor
(4) Fuel injection pump
(5) Suction control valve for the fuel injection pump
(6) Fuel temperature sensor
(7) Pressure relief valveThe fuel injection pump (4) feeds fuel to the high-pressure fuel manifold (rail) (2). The fuel is at a pressure of 200 MPa (29000 psi). A pressure sensor (6) in the high-pressure fuel manifold (rail) (2) monitors the fuel pressure in the high-pressure fuel manifold (rail) (2). The ECM controls a suction control valve (5) in the fuel injection pump (4) to maintain the actual pressure in the high-pressure fuel manifold (2) at the desired level. The high-pressure fuel is continuously available at each injector. The ECM determines the correct time for activation of the correct electronic unit injector (1) which allows fuel to be injected into the cylinder. The leakoff fuel from each injector passes into a pipe that is connected to each injector. The pipe is connected to the pressure relief valve (7) and the fuel injection pump (4) to return the leakoff fuel to the fuel tank.Components of the Fuel Injection System
The fuel system has the following mechanical components:
Primary filter/water separator
Electric transfer pump
Fuel injection pump
Fuel injectors
Fuel manifold
Pressure relief valve
Fuel pressure sensor
Fuel temperature sensorThe following list contains examples of both service and repairs when you must prime the system:
A fuel filter is changed.
A low-pressure fuel line is replaced.
The fuel injection pump is replaced.
The ECM is replaced.For the correct procedure to prime the fuel system, refer to Systems Operation, Testing and Adjusting, "Fuel System - Prime".Primary Filter/Water Separator
Illustration 3 g06004591
Typical example
Note: The primary filter/water separator is mounted on the application.The primary filter/water separator (1) is located between the fuel tank and the electric transfer pump. The primary filter/water separator (1) provides a 100 micron