TM-9-2320-361-24-1 Field Maintenance Manual Volume 1 for M44A2 Series Trucks
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TM 9-2320-361-24-1 0003 00 0003 00-4 THEORY OF OPERATION (Contd) 0003 00-4 0003 00-4 FUEL SYSTEM Fuel System Operation: The fuel system is the same on all models. It consists of one fuel injector per cylinder, an injector pump, which pressurizes and distributes fuel to each fuel injector, a fuel transfer pump, which forces fuel through the secondary and final fuel filters, and an in-tank electric fuel pump which draws fuel from the fuel tank and pumps it through the primary fuel filter and on to the fuel transfer pump. The major components of the fuel system are as follows: PRIMARY FUEL FILTER – First filter to remove water and dirt from fuel. FUEL SUPPLY LINE – Directs fuel from fuel pump in fuel tank to primary fuel filter, to fuel transfer pump, to secondary and final fuel filters, to fuel injector pump, and then to fuel injectors. FUEL LEVEL SENDING UNIT – Detects fuel level in fuel tank and sends an electrical signal to fuel gauge on instrument panel. FUEL TANK PUMP – Draws fuel from fuel tank and pumps it through fuel supply line. FUEL TANK – Stores fuel for vehicle use. FUEL RETURN LINE – Directs unused fuel back to fuel tank. VENT LINE – Allows clean air to enter fuel tank as fuel supply is used up. FUEL INJECTORS – Spray a fine mist of fuel into combustion chambers. FINAL FUEL FILTER – Removes additional dirt from fuel. SECONDARY FUEL FILTER – Removes additional dirt from fuel. FUEL TRANSFER PUMP – Forces flow of fuel through secondary and final fuel filters to the fuel injector pump. FUEL INJECTOR PUMP – Furnishes pressurized fuel to the fuel injectors. L K J I H G F E D C B A