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ENGINE
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B. FUEL FILTER
The Fuel filter is fitted as a second filtering step in
the fuel feed system. It is mainly used to filter out
particles that are present in the fuel.
For removal and refitment refer Engine on vehicle
repairs in this section.
! CAUTION
The fuel filter and fuel sedimentor should be re-
placed as recommended in the service schedule. If
this is not done, it may result in impurities or particles
entering the High pressure system causing damage
to the Fuel Injection components.
C. PRIMING PUMP
Priming pump is provided in the low pressure line
just before the fuel filter. It is used to prime the fuel
feed system with fuel. This is done in order to avoid
air lock in the system. The advantage is that the fuel
lines need not be loosened or dis-connected to bleed
the system. Priming can be done by pressing and
releasing the bulge repeatedly till it is filled with fuel.
Fuel System Priming Procedure:
If the performance of the engine is affected due to
the presence of the air in fuel system (commonly
known as air lock), then detect can be removed by
bleeding the fuel system. This can be done by pump-
ing the priming pump (Fig. 17) by hand.
Start engine and check for fuel leakage. Rectify if
necessary.
Check for smooth running of engine.
Whenever replacing fuel sedimentor or filter, use
priming pump to complete the fuel flow circuit.
NOTE
Do not loosen the HP lines for bleeding the air from
fuel system. Bleeding of the fuel system should be
done only using priming pump.
D. COMMON RAIL
It is a fuel reservoir where the fuel is maintained at a
pressure of about 1600 bar. The fuel is pumped into
it from the HP pump and gets delivered to the injec-
tors through the HP lines. It is also fitted with a rail
pressure
(RP)
sensor and the signal is used by EMS
ECU to maintain the fuel pressure.
NOTE
Whenever fuel rail is removed from the engine, al-
ways cover the inlet and outlet openings of the rail
with the protective caps.