Engine Tune-Lb
DETROIT DIESEL
The letters R or L indicate the injector location in the
adjusting screw (Fig. 2). If the setting is correct, the
right or left cylinder bank, viewed from the rear of the
.0015" movement can be seen by placing a few drops
of oil into the governor gap and pressing a screw
engine. Cylinders are numbered starting at the front
of the engine on each cylinder bank. Adjust the
driver against the gap adjusting screw. Movement of
No. 3L injector rack control lever first to establish a
the cap toward the plunger will force the oil from the
guide for adjusting the remaining injector rack control
gap in the form of a small bead.
levers.
7. Hold the gap adjusting screw and tighten the lock
nut.
1. Disconnect any linkage attached to the speed 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 the
when the nut is against the high-speed plunger.
governor cover.
CAUTION: A false fuel rack setting may result
if the idle speed adjusting screw is not backed
Position Injector Rack Control Lovers
out as noted above.
The position of the injector racks must be correctly set
NOTE: This adjustment lowers the tension of
in relation to the governor. Their position determines
the low-speed spring so it can be easily
the amount of fuel injected into each cylinder and
compressed. This permits closing the low speed
ensures equal distribution of the load.
gap without bending the fuel rods or causing
the yield mechanism springs to yield or stretch.
Properly positioned injector rack control levers with
the engine at full-load will result in the following:
3. Back out the buffer screw approximately 5/8", if it
has not already been done.
1. Speed control lever at the maximum speed position.
4. Remove the clevis pin from the fuel rod and the
2. Governor low-speed gap closed.
right cylinder bank injector control tube lever.
3. High-speed spring plunger on the seat in the
5. Loosen all of the inner and outer injector rack
governor control housing.
control lever adjusting screws on both injector control
tubes. Be sure all of the injector rack control levers are
4. Injector fuel control racks in the full-fuel position.
free on the injector control tubes.
6. Move the speed control lever to the maximum speed
position; hold it in that position with light finger
pressure. Turn the inner adjusting screw on the
Fig. 4 - Checking Rotating Movement of
Fig. 3 - Positioning No. 3L Injector Rack
Injector Control Rack
Control Lever
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