DETROIT DIESEL
Engine Tune Up
the cap toward the plunger will force the oil from the gap in the form of a small bead.
7.
Hold the gap adjusting screw and tighten the locknut.
8.
Recheck the gap and readjust if necessary
9.
Stop the engine and, using a new gasket, install the governor cover. The governor cover should be placed on the
housing with the pin of the speed control lever projecting into the slot of the differential lever.
10. Install the screws and lock washers finger tight. Pull the cover away from the engine and tighten the screws. This
step will properly locate the cover on the governor housing.
Position Injector Rack Control Levers
The position of the injector racks must be correctly set in relation to the governor. Their position determines the amount
of fuel injected into each cylinder and ensures equal distribution of the load. Properly positioned injector rack control
levers with the engine at full-load will result in the following:
1.
Speed control lever at the full-fuel position.
2.
Governor low-speed gap closed.
3.
High-speed spring plunger on the seat in the governor control housing.
4. Injector racks in the full-fuel position.
Adjust the rear injector rack control lever first to establish a guide for adjusting the remaining injector rack control levers.
1.
Disconnect any linkage attached to the speed control lever.
2.
Turn the idle speed adjusting screw until 1/2" of the threads (12-14 threads) project from the lock nut, when the nut
is against the high-speed plunger.
CAUTION: A false fuel rack setting may result if the idle speed adjusting screw is not backed out as noted above.
NOTE: This adjustment lowers the tension of the low-speed spring so it can be
easily compressed. This permits closing the low speed gap without bending the
fuel rods or causing the yield mechanism springs to yield or stretch.
Back out the buffer screw approximately 5/8", if it has not already been done.
Loosen all of the inner and outer injector rack control lever adjusting screws (Fig. 2). Be sure all of the levers are free on
the injector control tube.
Move the speed control lever to the maximum speed position. Turn the inner adjusting screw down on the rear injector
rack control lever until a step-up in effort is noted. This will place the rear injector rack in the full-fuel position. Turn down
the outer adjusting screw until it bottoms lightly on the injector control tube. Then alternately tighten both the inner and
outer adjusting screws. This should result in placing the governor linkage and control tube assembly in the
Fig. 3. Checking Injector Rack "Spring"
Fig. 4.
Checking Rotating Movement of
Injector Control Rack
Page 80
DETROIT DIESEL
Engine Tune Up
