ENGINE
79
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
pumping the priming pump 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
injectors 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, always cover the inlet and outlet
openings of the rail with the protective
caps.
e) Injector :
The injector used in VARICOR engine is a
solenoid operated injector. This is controlled by
the EMS ECU. The timing of injection and quantity
is controlled by the EMS ECU. It operates at a
pressure of 1600 bar. It makes multiple injections
(
2 pilot injections and 1 main injection)
with short
intervals between each injection.
The injector has a unique 20 digit hexadecimal
I3C code by which the EMS ECU recognizes it.
Whenever an injector is replaced, it should be re-
calibrated using the Diagnostic tool by entering
the I3C code.
For procedure refer EMS ECU
Diagnostic software users’ manual in this group.
NOTE
Injectors should not to be interchanged in
during service since individual injector
characterization is different and I3C no. of
each injector is written in the ECU during
engine assembly.




