Fuel Injection System Line Routing
(1) Fuel Tank
(2) Fuel Tank Fuel Pump Module
(3) Fuel Filter Assembly
(4) Diesel Fuel Separator
(5) Fuel Injection Pump
(6) Fuel Pressure Regulator 1 (Part of Fuel Injection Pump)
(7) Fuel Injection Fuel Rail Assembly
(8) Fuel Pressure Service Valve (Fuel Pressure Regulator 2)
(9) Fuel Pressure Regulator (Fuel Rail Pressure Sensor)
(10) Fuel Injector
(11) Constant Pressure Regulator (Part of Fuel Injection Fuel Return Hose)
The fuel tank (1) stores the fuel supply. An electric fuel pump module (2) mounted in the tank provides low pressure fuel to the injection pump, The engine control module (ECM) controls the fuel pump operation. Fuel is drawn through a strainer filter at the bottom of the fuel pump. through the rear fuel lines to the fuel filter assembly (3). The fuel filter assembly consists of a fuel filter/water separator, fuel heater, fuel temperature sensor and a water in fuel sensor. Fuel flows out of the fuel filter assembly through the front fuel lines to the fuel injection pump (5). The belt driven fuel injection pump is mounted on the upper right corner of the engine block. High pressure fuel is supplied through the high pressure fuel line to the fuel injection fuel rail assembly (7). Then through the fuel injector lines to the injectors (10). Fuel pressure is controlled by the ECM, fuel pressure regulator 1 (6) and fuel pressure service valve (8). Excess fuel is delivered to the fuel injection pump and injectors to lubricate and cool the components. The fuel injectors require pressure on the return side for proper operation, this is attained by using a constant pressure regulator (11) located in the fuel injection fuel return hose. Excess fuel then returns to the fuel tank through the return lines.