0331927 JOHNSON CLAMP, Timer base

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(1) Fuel tank (2) Primary fuel filter and water separator (3) Electric primping pump (4) Fuel cooled ECM (5) Secondary fuel filter (6) Low-pressure fuel pressure sensor (7) Fuel cooler (8) High-pressure fuel pump (9) High-pressure fuel rail (10) High-pressure fuel pressure sensor (11) Fuel injector (12) Fuel injector return line (13) High-pressure relief valve (14) Fuel transfer pump
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(2) Primary fuel filter and water separator (4) Fuel cooled ECM (5) Secondary fuel filter (6) Low-pressure fuel pressure sensor (7) Fuel cooler (8) High-pressure fuel pump (9) High-pressure fuel rail (10) High-pressure fuel pressure sensor (11) Fuel injector (13) High-pressure relief valve (14) Fuel transfer pumpThis fuel system consists of five major components:
High-pressure fuel pump (8)
Engine Control Module (ECM) (4)
Fuel Injectors (11)
Fuel rail (9)
Fuel transfer pump (14) Fuel System Operation
The transfer pump (14) pulls fuel from the fuel tank (1) through the fuel filter/ water separator priming pump (14). Transfer pump (14) sends the fuel through the ECM in order to cool the ECM. Fuel pressure sensor (6) measures the fuel pressure at the inlet of the primary fuel filter. The fuel flows through the primary fuel filter (5) to the fuel cooler (7) to the high-pressure fuel pump (8). The high-pressure fuel pump (8) pressurizes the fuel that is sent to the fuel rail (9). The fuel rail (9) distributes the fuel to the fuel injectors (11) by the use of fuel lines. The fuel rail uses a fuel pressure sensor (10) that tells the ECM (4) the pressure of the fuel rail. The ECM receives engine speed from the speed/timing sensor. The ECM controls the solenoids for the high-pressure fuel pump (8) in order 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 in order 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 located 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 in order to adjust the fuel delivery, injection pressure, and injection timing. The ECM contains programmed performance maps (software) in order 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
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(2) Primary fuel filter (3) Electric priming pump (15) Priming pump/fuel filter inlet (16) Priming pump/fuel filter outlet (17) Water separator
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(18) Air purge valveThe electric priming pump (3) 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 (18) on the fuel filter base is usually required only after servicing the fuel system or a fuel system filter change.. When the fuel system has air trapped in the fuel filters, lines, and other fuel system components, the engine could experience difficulty starting. The ECM electronically controls the fuel priming pump relay. The fuel priming pump runs for 150 seconds after the keyswitch is turned to the ON or remote start position unless the engine reaches low idle rpm. Once one of these conditions are met, the engine speed has to come back to zero to start the priming cycle again.Fuel Transfer Pump
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(8) High-pressure fuel pump (14) Fuel transfer pump (19) Low-pressure fuel inlet (20) Low-pressure fuel outletFuel transfer pump (14) is a pump that produces low pressure, high volume to pull fuel from the tank and through the primary fuel filter. Then, the pump sends the fuel through the secondary filter on the way to the high-pressure fuel pump. The high-pressure fuel pump feeds the injectors.Fuel transfer pump (14) is mounted on the back of high-pressure fuel pump (8). The fuel transfer pump is driven by the shaft of the high-pressure fuel pump.High-pressure fuel pump
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(8) High-pressure fuel pump (21) High-pressure fuel inlet (22) Pressure regulator (23) High-pressure fuel outlet
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Cross section of the high-pressure fuel pump (14) Fuel transfer pump (24) Camshaft with three lobes (25) Fuel pump piston (26) Fuel pump cylinder (27) Ball delivery valve (28) Camshaft lobeHigh-pressure fuel pump (8) pressurizes the fuel to 25 MPa to 180 MPa. The high-pressure fuel pump is located at the left front cor