Engine Tune-Up
DETROIT DIESEL
10. When all of the injector .rack control levers are
lever in the run position and press down on the injector
adjusted, recheck their settings. With the control tube
rack with a screw driver or finger tip and note the
lever in the full-fuel position, check each control rack as
"rotating" movement of the injector control rack (Fig. 4).
in Step S. All of the control racks must have the same
Hold the stop lever in the run position and, using a
"spring" condition with the control tube lever in the full-
screw driver, press downward on the injector control
fuel position.
rack. The rack should tilt downward (Fig. 5) and when
the pressure of the screw driver is released, the control
11. Insert the levis pin in the fuel rods and the injector
rack should "spring" back upward. If the rack does not
control tube levers.
return to its original position, it is too loose. To correct
this condition, back off the outer adjusting screw slightly
12. Use new gaskets and install the valve rocker covers.
and tighten the inner adjusting screw. The setting is too
tight if, when moving the stop lever from the stop to the
Adjust Maximum, No Load Speed
run position, the injector rack becomes tight before the
governor stop lever reaches the end of its travel. This
will result in a stepup in effort required to move the stop
All governors are properly adjusted before leaving the
lever to the run position and a deflection in the fuel rod
factory.
However, if the governor has been
(fuel rod deflection can be seen at the bend). If the rack
reconditioned or replaced, and to ensure the engine
is found to be too tight, back off the inner adjusting
speed will not exceed the recommended no-load speed
screw slightly and tighten the outer adjusting screw.
as given on the engine option plate, the maximum no-
load speed may be set as follows: Start the engine and
6. Remove the clevis pin from the fuel rod and the left
after it reaches normal operating temperature,
bank injector control tube lever.
determine the maximum no-load speed of the engine
with an accurate tachometer. Then stop the engine and
7. Insert the clevis pin in the fuel rod and the right
make the following adjustments, if required.
cylinder bank injector control tube lever and position the
No. 3R injector rack control lever as previously outlined
1. Refer to Fig. 9 and disconnect the booster spring
in Step 4 for the No. 3L control lever.
and the stop lever retracting spring.
8. Insert the clevis pin in the fuel rod and the left bank
2. Remove the variable speed spring housing and the
injector control tube lever. Repeat the check on the 3L
spring retainer, located inside of the housing, from the
and 3R injector rack control levers as outlined in Step 5.
governor housing.
Check for and eliminate any deflection which may occur
at the bend in the fuel rod where it enters the cylinder
3. Refer to Table 1 and determine the stops or shims
head.
required for the desired full-load speed. A split stop can
only be used with a solid stop (Fig. 6).
9. To adjust the remaining injector rack control levers,
remove the clevis pin from the fuel rods and the injector
4. Install the variable speed spring retainer and
control tube levers, hold the injector control racks in the
housing and tighten the two bolts.
full-fuel position by means of the lever on the end of the
control tube and proceed as follows:
a. Turn down the inner adjusting screw of the
injector rack control lever until the screw
bottoms (injector control rack in the full-fuel
position).
b. Turn down the outer adjusting screw of the
injector rack control lever until it bottoms on the
injector control tube.
c. While still holding the control tube lever in the
full-fuel position, adjust the inner and outer
adjusting screws to obtain the same condition as
outlined in Step 5. Tighten the screws.
Fig. 6 - Location of Shims and Stop
CAUTION: Once the No. 3L and No. 3R
injector rack control levers are adjusted,
do not try to alter their settings. All
adjustments are made on the remaining
control racks.
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