1. Aims, objectives and disclaimer:
The aim of this presentation is to give a generic
technical overview of the main features and
operating principles of the common rail diesel fuel
injection system. The objectives are that by the end of
this presentation, you will have gained a working
knowledge and understanding of the fundamental
principles of common rail diesel fuel systems.
2. Common Rail is a direct fuel injection system
used in Diesel engines. Common Rail Diesel
systems can now grant maximum
performances and reliability to automotive
engines, reducing noise and emissions.
The system is composed of an injection pump,
the rail, injectors and sensors which detect the
operating conditions of the engine for a
centralized electronic unit (ECU) which
manages all the components.
3.
4. Electric fuel pump
electric fuel pump is used on engines with
fuel injection to pump fuel from the gas
tank to the injectors. The pump must
deliver the fuel under high pressure
(typically 30 to 85 psi depending on the
application) so the injectors can spray the
fuel into the engine
The primary purpose of a diesel fuel filter is to
protect the fuel system components of the
engine. A diesel fuel filter must be designed to
remove extremely small particles to prevent the
premature failure of these components
Fuel filter
The purpose of the high-pressure fuel pump, in
combination with the low-pressure fuel pump, is to
provide gas to the vehicle's engine from the tank. A
failure of high-pressure fuel pump can have
significant impacts on your vehicle's performance.
High pressure fuel pump
To adapt the fuel pressure in the rail,
the fuel metering valve on the
mechanical fuel pump controls the
amount of fuel entering the pump. The
plunger is held fully open by a spring to
let fuel pass through.
Fuel metering control valve
At engine start and for preheating the fuel when
temperatures are low, the rail pressure is
controlled by the PCV. To heat up the fuel
quickly, the high-pressure pump delivers and
compresses more fuel than is needed and the
excess fuel is discharged by the PCV into the
fuel return.
Fuel rail pressure control valve
The fuel rail pressure sensor is responsible
for analyzing the pressure of the fuel that is
inside the rail of the fuel pump assembly. This
sensor is an electronic device which calculates
the fuel pressure and then sends this
information to the PCM (powertrain control
module)
Fuel rail pressure sensor
A fuel rail is high pressure tubing which takes
fuel to the injectors in an internal combustion
engine. The fuel passes from the fuel rail into
the injectors in metal fuel pipes.
Common rail
Fuel injectors
The job of the injectors is to deliver a precise
amount of atomized and pressurized fuel into
each cylinder. Highly atomized, pressurized
fuel distributed evenly throughout the cylinder
results in increased power and fuel economy,
decreased engine noise, and smoother
operation.
