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180 Vasile Gabriel Nenerica et al.
2. Better fuel spraying is due to high pressure injection that is achieved
during injection (allow the use of same smaller nozzle holes). Such a method is
shown in Fig. 1.
Fig.1 – How to increase flowrate (www.delphi.com).
In the old injection system injection pressure was limited by structural
considerations as follows: the long distance of pipelines from the fuel pump to
the injection pressure limited the increase because of the debt resonance
phenomena which could occur in the pipeline. Even when the engine is stopped
the fuel from common rail pressure is the same so that when it is needed to be
sent to the injector in the shortest time. As a result a second ignition called post
combustion is now possible by using a small amount of diesel fuel in the main
explosive phase on loads of fuel injectors.The result is that it eliminates unburnt
diesel particles after the first explosion reducing hazards through a catalytic
heating installation faster.
3. Reduction of fuel consumption, a doubling of torque at low revs and
increases up to 25% of engine power. It also reduces noise and vibration level
specific to Macs.
4. Better control of injection timing leads to a quieter running engine, a
better performance with a lower consumption;
5. High reliability of engines equipped with such a system.
The system consists of a fuel tank, electric fuel pump (which may exist or
not) that serves to bring fuel from the tank through a filter to the high-pressure
pump, the high pressure pump, a common rail, pipeline and injectors. On cars
fitted with electric pump, when running out of fuel (it was a big problem of