MAINTENANCE MANUAL OF ENGINE
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5. Inspecting the fuel system
The fuel system, through the fuel delivery
pump, delivers the fuel into the high pressure fuel
pump from the fuel tank and via the fuel filter and
low pressure fuel line, and then the fuel is pumped
by the high pressure pump into the high pressure
pipe and is injected into the cylinder (at pressure of
21-23MPa) by the fuel injector, then compressed
and fired in the cylinder; The excessive fuel flows
back to the fuel tank via the fuel return pipe of the
fuel injector.
Attention:
1. The fuel pressure in the fuel injection pump,
high pressure fuel pipe and fuel injector remains
very high, so that loosening any pipe connection is
not allowed during operation of the engine. Other-
wise, it may result in serious personal injury and
damage to property.
2. After stopping the engine, wait for at least
10 minutes, and slowly loosen the pipe connection
of the high pressure fuel system after the fuel pres-
sure is reduced. Connect a pressure gauge to meas-
ure and inspect the fuel pressure.