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Fuel System
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6. Tighten the adjusting screw of the additional spring until the
idling speed rises to the rated value. Lock the adjusting screw
in this position.
7. Fix the safety caps of the adjusting screws.
Note!
Other adjustments (output and max. speed) of the in-
jection pump can only be performed by a specially trained
person who has the necessary special tools and gaugesavail-
able.
L. Removing injectors
1. Clean the injectors and the area around them. Disconnect
the delivery pipes and the leak---off pipes.
9051 71300
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2. Remove the injector attaching nuts and remove the injector
from the cylinder head. Fit protective plugs to all connections.
If the injector does not rise by hand, use puller 9051 71300.
3. Remove the sealing washers from the bottom of the injector
location in the cylinder head if they do no come out with the
injector.
M. Inspecting injectors
Note! When pressure testing the injectors, it is important
to avoid the nozzle end as the fuel jetting out easily pen-
etrates the skin. Also bear in mind that the fuel ”mist” is
dangerous to inhale.
1. Clean the injector with cleaning fluid and a soft brush.
The carbon deposits must not be knocked off or removed in
any other way which may damage the nozzle.
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2. Secure the injector in a test bench and check the follow-
ing:
--- injector opening pressure
--- the properties of the chattering (creaking) sound and the
form of the spray pattern
--- sealing of nozzle valve against its seat
Opening pressure
Pump a few times to fill the injector. Increase the pressure in
the injector until the chattering (creaking) sound becomes
audible. Read off the opening pressure of the injector. If the
opening pressure deviates from the given value, the injector
should be taken apart and checked.
Adjustment is achieved by changing the shim. The thickness
of the shims varies from 1,00...1,90 mm and they are available
in increments of 0,05 mm. A thicker shim will raise the opening
pressure while a thinner one lowers it. A difference in shim
thickness of 0,05 mm changes the opening pressure by ap-
prox. 5,0 bar. As the opening pressure of the injector drops
slightly after adjustment, the opening pressure should be set
to approximately 10 bar above the value given in the specifica-
tions. This value applies both to new and used injector.