Operation Manual of WEICHAI GENSET
and affecting the smooth operation
of the engine.
Incorrect injection timing, poor
7
atomization and uneven injection Check and adjust it.
pressure of nozzle
13. Engine overspeed
Under normal operation, the engine speed suddenly rises and exceeds the rated speed,
and cannot be controlled; the engine generates loud roar and emits a lot of black
smoke or blue smoke from the exhaust pipe.
The fundamental cause of diesel engine overspeed is the loss or changes in the speed
regulation characteristics. Faults of fuel injection pump and governor, such as sticking
or loosening of related parts, will cause excessive supply and make them lose normal
speed regulation characteristics. However, the extra diesel or oil in the combustion
chamber will change the speed regulation characteristics of diesel engine.
S/N Fault
Treatment method
During maintenance and
assembling, the fuel injection pump
plunger may not rotate smoothly or
be stuck at the maximum supply
position in case of the damage of
fuel injection pump plunger and
1
outlet valve seat, deformation of
plunger sleeve due to excessive
Check and adjust it.
tightening torque, entry of foreign
matters into the clearance of
plunger pair, excessively thin spacer
on the positioning bolt of plunger
sleeve or long bolt jacking the
plunger sleeve.
The fixing screw for the fuel
2
quantity adjusting gear ring of the
fuel injection pump plunger is loose,
Check and adjust it.
making the plunger out of control.
The plunger regulating arm of fuel
injection pump or the ball head of
3
rack adjusting arm does not enter
into the groove of adjusting fork, so
Check and adjust it.
that the plunger is in the maximum
supply position.
4
The oil supply adjusting rack and the
moving part of the governor are
Check and adjust it.
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