Engine Tune-Up
DETROIT DIESEL
the cap toward the plunger will force the oil from the gap
establish a guide for adjusting the remaining injector
in the form of a small bead.
rack control levers.
7.
Hold the gap adjusting screw and tighten the
1.
Disconnect any linkage attached to the speed
lock nut.
control lever.
8.
Recheck the gap and readjust if necessary.
2.
Turn the idle speed adjusting screw until 1/2"of
the threads (12-14 threads) project from the lock nut,
9.
Stop the engine and, using a new gasket, install
when the nut is against the high-speed plunger.
the governor cover. The governor cover should be
placed on the housing with the pin of the speed control
CAUTION: A false fuel rack setting may result if
lever projecting into the slot of the differential lever.
the idle speed adjusting screw is not backed out
as noted above.
10.
Install the screws and lock washers finger tight.
Pull the cover away from the engine and tighten the
NOTE: This adjustment lowers the tension of
screws. This step will properly locate the cover on the
the low-speed spring so it can be easily
governor housing.
compressed.
This permits closing the low
speed gap without bending the fuel rods or
Position Injector Rack Control Levers
causing the yield mechanism springs to yield or
stretch.
The position of the injector racks must be correctly set in
relation to the governor. Their position determines the
3.
Back out the buffer screw approximately 5/8", if
amount of fuel injected into each cylinder and ensures
it has not already been done.
equal distribution of the load. Properly positioned
injector rack control levers with the engine at full-load
4.
Loosen all of the inner and outer injector rack
will result in the following:
control lever adjusting screws (Fig. 2). Be sure all of
the levers are free on the injector control tube.
1.
Speed control lever at the full-fuel position.
5.
Move the speed control lever to the maximum
2.
Governor low-speed gap closed.
speed position. Turn the inner adjusting screw down on
the rear injector rack control lever until a step-up in
3.
High-speed spring plunger on the seat in the
effort is noted. This will place the rear injector rack in
governor control housing.
the full-fuel position. Turn down the outer adjusting
screw until it bottoms lightly on the injector control tube.
4.
Injector racks in the full-fuel position. Adjust the
Then alternately tighten both the inner and outer
rear injector rack control lever first to
adjusting screws. This should result in placing the
governor linkage and control tube assembly in the
Fig. 3 - Checking Rotating Movement of
Injector Control Rack
Fig. 4 - Checking Injector Rack "Sprint"
Page 78
