3239196 - Introduction - FUEL TANK AND PIPES
CONSTRUCTION FEATURES
The fuel supply system is divided into a
low pressure circuit and a high pressure circuit.The low pressure circuit consists
of:
- submerged auxiliary pump complete with fuel level gauge,
pressure regulator and fuel filter
- external fule filter
The high pressure circuit consists
of:
- pressure pump
- high pressure pipe (to be replaced whenever disassembled);
- distribution manifold (rail) with pressure regulator
and fuel pressure sensor;
- injectors.
The pressure regulator incorporated in the
fuel pump assembly is calibrated at 4.5 bar.With the ignition ON, the pressure of 4.5
bar is present throughout the low pressure and high pressure lines and
the pressure regulator is closed in these conditions.Starting takes place with the pressure in
the rail at around 4.5 bar because the high pressure pump is not capable
of supplying high pressures instantly.When the engine is started, durin idling,
the fuel pressure in the rail is around 50 bar.During operation, the pressure in the rail
can reach a maximum value of 100 bar depending on the engine load
and the performance required by the driver.When the engine is switched off, the pressure
in the rail gradually decreases (via the high pressure pump) until
it reaches 4.5 bar (pressure regulator setting).The maximum pressure produced by the high
pressure pump is around 120 bar (if the pressure regulator is stuck).The system is equipped with an inertia switch
which, in the case of an impact to the vehicle, cuts off the supply
from the electric fuel pump.The pipes are secured to the underbody with
special collars and enclosed by protections.FUEL SUPPLY SYSTEM
1 - Fuel tank
2 - Immersed pump unit complete with fuel gauge sender unit
3 - Fuel filler pipe
4 - Supplementary fuel filter
5 - High pressure fuel pump
6 - High pressure pipe
7 - Distribution manifold
8 - Pressure sensor
9 - Pressure regulator
10 - Fuel injectors
11 - Spacer
12 - Low pressure pipe
