THEORY OF OPERATION - continued - TM-9-2320-361-24-10066

TM 9-2320-361-24-1

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THEORY OF OPERATION (Contd)

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:

A PRIMARY FUEL FILTER First filter to remove water and dirt from fuel.

B 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.

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