ELBOW-FLARED 6K1972 - Caterpillar

Illustration 1 g01565594
(1) Electronic unit injector (2) Heat exchanger (3) Cylinder heads (4) Fuel tank (5) Primary fuel filter and water separator (6) Fuel transfer pump (7) Electronic Control Module (ECM) (8) Fuel priming pump and secondary fuel filterNote: The fuel cooler is part of the heat exchanger. , The fuel cooler is optional on Tier I engines with prefixes (S/N: RNC) and (S/N: T3T). The fuel cooler is standard for Tier II engines that are rated pleasure craft with the prefixes (S/N: RNR) and (S/N: RNZ).The fuel supply circuit is a conventional design for unit injector diesel engines. The system consists of the following major components that are used to deliver low pressure fuel to the unit injectors:Fuel tank - The fuel tank is used to store the fuel.Fuel priming pump - The fuel priming pump is used to evacuate the air from the fuel system. As the air is removed the system fills with fuel.Fuel filters - The primary fuel filter is used to remove abrasive material and contamination from the fuel system that may be large enough to damage the fuel transfer pump. The secondary fuel filter is used to remove abrasive material and contamination as small as two microns that could damage the injectors.Supply lines and return lines - Supply lines and return lines are used to deliver the fuel to the different components.The purpose of the low pressure fuel supply circuit is to supply fuel that has been filtered to the fuel injectors at a rate that is constant and a pressure that is constant. The fuel system is also utilized to cool components such as the fuel injectors and the Electronic Control Module (ECM).Once the injectors receive the low pressure fuel, the fuel is pressurized again before the fuel is injected into the cylinder. The unit injector uses mechanical energy that is provided by the camshaft to achieve pressures that can be in excess of 200000 kPa (30000 psi).Control of the fuel delivery is managed by the engine's ECM. Data from several of the engine systems is collected by the ECM and processed