Engine Tune-Up
DETROIT DIESEL
pin in the throttle shaft assembly entering the slot
in the differential lever.
b. Install the four cover screws and lock washers
finger tight.
c. Pull the cover assembly in a direction away from
the engine, to take up the slack, and tighten the
cover screws.
NOTE: This step is required since no dowels are
used to locate the cover on the housing.
Position Injector Rack Control Levers
The position of the injector control rack levers must be
correctly set in relation to the governor. Their position
determines the amount of fuel injected into each
Fig. 4 - Checking Injector Control Rack
cylinder and ensures equal distribution of the load.
"Sprint"
Properly positioned injector control rack levers with
the engine at full-load will result in the following:
3. Move the stop lever to the RUN position and hold it
in that position with light finger pressure. Turn the
1. Speed control lever at the maximum speed position.
inner adjusting screw of the rear injector rack control
lever down until a slight movement of the control tube
2. Stop lever in the RUN position.
is observed or a step-up in effort to turn the screw
driver is noted. This will place the rear injector rack in
3. Injector fuel control racks in the full-fuel position.
the full-fuel position. Turn the outer adjusting screw
down until it bottoms lightly on the injector control
Adjust the rear injector rack control lever first to
tube. Then alternately tighten both the inner and outer
establish a guide for adjusting the remaining levers.
adjusting screws. This should result in placing the
governor linkage and control tube in the respective
1. Loosen all of the inner and outer injector rack
positions that they will attain while the engine is
control lever adjusting screws (Fig. 2). Be sure all of
running at full load.
the levers are free on the injector control tube.
NOTE: Overtightening of the injector rack
2. Move the speed control lever to the maximum speed
control lever adjusting screws during installa-
position.
tion or adjustment can result in damage to the
injector control tube. The recommended torque
of the adjusting screws is 24-36 in-lbs (3-4 Nm).
4. To be sure of proper rack adjustment, hold the stop
lever in the RUN position and press down on the
injector rack with a screw driver or finger tip and note
"rotating" movement of the injector control rack
(Fig. 3). Hold the stop lever in the RUN position and,
using a screw driver, press downward on the injector
control rack. The rack should tilt downward (Fig. 4)
and, when the pressure of the screw driver is released,
the control rack should "spring" back upward.
If the rack does not return to its original position, it is
too loose. To correct this condition, back off the outer
adjusting screw slightly and tighten the inner adjusting
screw. The setting is too tight if, when moving the stop
Fig. 3 - Checking Rotating Movement of
lever from the STOP to the RUN position, the injector
Injector Control Rack
rack becomes tight before the stop lever reaches the
end of its travel. This will result in a step-up in effort
Pago 94
