Page 351 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

In a fuel supply system, the low-pressure circuit is responsible for delivering fuel from the fuel tank to the high-
pressure circuit, typically found in systems like CRDI. This circuit consists of components such as the fuel tank,
fuel filter, fuel pump, and fuel lines. The fuel pump, usually submerged in the fuel tank, draws fuel and sends it
through the fuel filter to remove impurities. From there, the fuel is delivered to the high-pressure pump or fuel
rail, where it undergoes pressurization before being injected into the engine cylinders. The low- pressure circuit
ensures a steady supply of clean fuel to the high-pressure circuit, optimizing engine performance and longevity.
Parts: Fuel tank, Fuel log, Carburetor, Bypass fuel pressure regulator, Inline fuel pump,
High pressure fuel supply circuit: In a common rail direct injection (CRDI) system, the high-pressure line
circuit is a crucial component responsible for delivering pressurized fuel to the fuel injectors. This circuit typically
consists of high-pressure fuel lines, a fuel rail, a high-pressure pump, and fuel injectors. The high-pressure pump
pressurizes the fuel, which is then stored in the fuel rail before being delivered to the injectors. This setup allows
for precise control over the timing and quantity of fuel injection, enhancing engine performance and fuel efficiency.

Parts: Injector, high pressure pipe, Pressure sensor, Common rail, Pressure limitter, Fuel intake volume control
valve, Supply pump, Fuel return pipe

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CITS : Automotive - Mechanic Diesel - Lesson 108 - 113