Common Rail Injection - Mercedes-Benz OM 651 Service Manual

Common rail injection

Injection technology
Engine 651 uses the new Common Rail technology of
the second generation from Delphi. The maximum
injection pressure has been increased by 400 bar to
2,000 bar. A new feature is the piezo injector concept
with direct nozzle needle control. Direct actuation
allows the injection volume to be changed quickly and
with the utmost precision.
The piezo injectors provide the following improve-
ments:
• Greater flexibility for actuation of injection timing
points
• Lower fuel consumption
• Higher engine output
• Minimized combustion noise
• Reduced emissions
• Smoother engine running
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Introduction of New Generation of 4-Cylinder Inline Engines, OM 651
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– This printout will not be recorded by the update service. Status: 09 / 2008 –
The most important new features of the injection
system include:
• High-pressure pump with two pump elements
(max. injection pressure 2,000 bar)
• Electronic engine control with more advanced
actuation function for injection timing points
• Leak oil-free injection system with piezo injectors
The increase in engine output to 150 kW / 204 hp and
the increase in engine torque to 500 Nm was only
made possible by the increased pressure potential. At
the same time, the level of raw emissions produced by
the engine has been significantly improved.