Fiori DB 460, Use And Maintenance Manual

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SEBU8325-01 67
Maintenance Section
Fuel Injector - Test/Change
Refer to Systems Operation/Testing and Adjusting,
“Engine Valve Lash - Inspect/Adjust” for more
information.
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Fuel Injector - Test/Change
Fuel leaked or spilled onto hot surfaces or electri-
cal components can cause a fire.
NOTICE
Do not allow dirt to enter the fuel system. Thoroughly
clean the area around a fuel system component that
will be disconnected. Fit a suitable cover over discon-
nected fuel system component.
NOTICE
If a fuel injector is suspected of operating outside of
normal parameters it should be removed by a qualified
technician. The suspect fuel injector should be taken
to an authorised agent for inspection.
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Illustration 35
Typical fuel Injector
The fuel injectors should not be cleaned as cleaning
with incorrect tools can damage the nozzle. The fuel
injectors should be renewed only if a fault with the
fuel injectors occurs. Some of the problems that may
indicate that new fuel injectors are needed are listed
below:
• The engine will not start or the engine is difficult
to start.
• Not enough power
•
The engine misfires or the engine runs erratically.
• High fuel consumption
• Black exhaust smoke
•
The engine knocks or there is vibration in the
engine.
• Excessive engine temperature
Removal and Installation of the
Fuel Injectors
Work carefully around an engine that is running.
Engine parts that are hot, or parts that are moving,
can cause personal injury.
Make sure that you wear eye protection at all
times during testing. When fuel injection nozzles
are tested, test fluids travel through the orifices
of the nozzle tip with high pressure. Under this
amount of pressure, the test fluid can pierce the
skin and cause serious injury to the operator.
Always keep the tip of the fuel injection nozzle
pointed away from the operator and into the fuel
collector and extension.
NOTICE
If your skin comes into contact with high pressure fuel,
obtain medical assistence immediately.
Operate the engine at a fast idle speed in order to
identify the faulty fuel injector. Individually loosen and
tighten the union nut for the high pressure pipe to
each fuel injector. Do not loosen the union nut more
than half a turn. There will be little effect on the engine
speed when the union nut to the faulty fuel injection
nozzle is loosened. Refer to the Disassembly and
Assembly Manual for more information. Consult your
authorized Perkins dealer or your Perkins distributor
for assistance.