SUPPORT GP-ENGINE 7W6541 - Caterpillar

inlet to engine
(26) Electric priming pump with filter, water separator, and water-in-fuel switch
(27) Fuel Cooler
(28) Fuel outlet from engineThis fuel system consists of five major components:
High-pressure fuel pump (13)
Engine Control Module (ECM) (1)
Fuel Injectors (23)
Fuel rail (22)
Fuel transfer pump (20)
Priming pump (26)Fuel System Operation
The transfer pump (20) pulls fuel from the fuel tank (1) through the fuel filter/ water separator priming pump (25). Transfer pump (20) sends the fuel through the ECM to cool the ECM. Fuel pressure sensor (17) measures the fuel pressure at the inlet of the fuel filter. The fuel flows through the main fuel filter (2) to the high-pressure fuel pump (13). The high-pressure fuel pump (13) pressurizes the fuel that is sent to the fuel rail (22). The fuel rail (22) distributes the fuel to the fuel injectors (23) by the use of fuel lines. The fuel rail uses a rail pressure sensor (10) that tells the ECM (1) the pressure of the fuel rail. The ECM receives engine speed from the speed/timing sensor. The ECM controls the pressure regulator for the high-pressure fuel pump (14) to obtain the correct amount of pressure. If pressure at the fuel rail is too high, the pressure relief valve (13) opens. This valve opening drains the excess fuel back to the fuel tank. The rail pressure can vary from 25 MPa to 180 MPa. Once the fuel reaches the injectors, ECM sends current to the injector solenoid to actuate the three-way valve inside the injector. As the valve opens, the fuel flows from the high-pressure line to the tip. As the valve opening pressure is reached, the check is lifted and fuel is delivered at high pressure into the combustion chamber. The fuel is then delivered in a precise quantity and at the right time. The injector returns the excess fuel to the tank through a check valve and a pressure regulator.Component Description
Engine Control Module (ECM)
Engine Control Module (ECM) is on the left side of the engine. The ECM is a powerful computer that provides total electronic control of engine performance. The ECM uses data from engine performance that is gathered by several sensors. Then, the ECM uses this data to adjust the fuel delivery, injection pressure, and injection timing. The ECM contains programmed performance maps (software) to define horsepower, torque curves, and rpm. This software is commonly called the personality module.ECM logs faults of engine performance. Also, the ECM can run several diagnostic tests automatically when the ECM is used with an electronic service tool such as the Cat ET.Priming Pump
Illustration 3 g06018481
(29) Priming pump/fuel filter inlet
(30) Priming pump/fuel filter outlet
(31) Electric priming pump
(32) Primary fuel filter
(33) Water separator
Illustration 4 g06018490
(34) Air purge valveThe electric priming pump forces the air that is in the fuel system out of the system through manually operated valve on the fuel filter base. Priming via the manually operated air purge valve (32) on the fuel filter base is required only after servicing the fuel system or a fuel system filter