SERVICE MANUAL
ROBERT BOSCH MODEL MW INJECTION PUMP
Section 11
Engine Stop (No Delivery)
To stop the engine, plungers are rotated so that vertical
slots (stop slots) are in line with barrel ports. As plunger
moves up and down, fuel is transferred back and forth
from top of plunger through vertical sl6ts into charging
gallery. The ports do not close, thus, no delivery.
Plungers are rotated to the various metering positions by
the control rack. Rack movement is controlled by the
shutoff lever to stop the engine.
Figure 15. - Metering Positions
1.
Start Position (Charging Port Closed)
2.
Idle Position (Charging Port Closed)
3.
Full Load Position (Charging Port Closed)
4.
Stop Position (Charging Port Open)
5.
Effective Stroke
6.
Charging Port Position
EXTERNAL INJECTION PUMP CONTROLS
(Figure 16)
Prior to starting the engine, the injection pump shutoff
lever must be moved to the "run" position. this lever is
moved to the "run" position from the "shutoff" position by
an engine mounted electric shutoff or by a pull cable. An
electric shutoff is standard on some engines such as
in the Cargostar. DT- 466C truck engines which were
originally equipped with a cable shutoff, can be
converted to an electric shutoff in the field.
During injection pump calibration, the "shut- off" lever
position is established by positioning the shutoff lever
adjusting screw. The shutoff screw should not be moved
after calibration because fuel delivery might not be
completely stopped or the internal rack might be bent.
Electric shutoff and cable linkage adjustments must also
allow full control rack travel when the shutoff lever should
be in the "run" position. Follow the linkage adjustment
procedures in the on-engine repairs section to ensure full
rack travel during engine operation.
Driver accelerator pedal movements are transmitted
through a cable to the engine. Depending upon engine
application, the cable is connected directly to the
injection pump control lever or to engine mounted
linkage which is connected to the control lever at full
pedal depression, the control lever must contact the high
idle stop to allow full rack travel and maximum engine
power output.
Figure 16. - External Injection Pump Controls
The high idle stop is sealed at the engine production
plant. Adjustments to high idle speed should be made in
accordance with existing warranty policies. High idle
speed can only be raised a small amount by adjusting
the high idle screw even if the screw is completely
removed.
CGES-185-3
PRINTED IN UNITED STATES OF AMERICA
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