Engine Tune-Up
DETROIT DIESEL
determines the amount of fuel injected into each
7. Loosen the nut which locks the ball joint on the fuel
cylinder and ensures equal distribution of the load.
rod. Hold the fuel rod in the full-fuel position and
Adjust the rear injector rack control lever first to
adjust the ball joint until it is aligned and will slide on
establish a guide for adjusting the remaining levers.
the ball stud on the stop lever (Fig. 4). Position the
shutdown cable clip and tighten the fuel rod lock nut
1. Clean and remove the valve rocker cover. Discard
to retain the adjustment.
the gasket.
8. Check the adjustment by pushing the fuel rod
2. Disconnect the fuel rod at the stop lever.
toward the engine and make sure the injector control
rack is in the full-fuel position. If necessary, readjust
3. Loosen all of the inner and outer injector rack
the fuel rod.
control lever adjusting screws. Be sure all of the
injector rack control levers are free on the injector
9. Manually hold the rear injector rack in the full-fuel
control tube.
position, with the lever on the injector control tube,
and turn the inner adjusting screw of the adjacent
4. Move the speed control lever to the maximum speed
injector rack control lever down until the injector rack
position.
moves into the full-fuel position. Turn the outer
adjusting screw down until it bottoms lightly on the
5. Adjust the rear cylinder injector rack control lever
injector control tube. Then alternately tighten both the
adjusting screws (Fig. 3) until both screws are equal in
inner and outer adjusting screws.
height and tight on the injector control tube.
NOTE: Overtightening of the injector rack
6. Move the rear injector control rack into the full-fuel
position and note the clearance between the fuel rod
control lever adjusting screws during installa-
and the cylinder head bolt. The clearance should be
tion or adjustment can result in damage to the
1/32" or more. If necessary, readjust the injector rack
injector control tube. The recommended torque
adjusting screws until a clearance of at least 1/32" to
of the adjusting screws is 24-36 in-lbs (3-4 Nm).
1/16" exists. Tighten the adjustment screws.
10. Recheck the rear injector rack to be sure that it has
remained snug on the ball end of the rack control
lever while adjusting the adjacent injector rack. If the
rack of the rear injector has become loose, back off the
inner adjusting screw slightly on the adjacent injector
rack control lever and tighten the outer adjusting
screw. When the settings are correct, the racks of both
injectors must be snug on the ball end of their
respective control levers.
Fig. 3 Adjusting Injector Rack Control Lever
Adjusting Screws
Fig. 4 Adjusting Fuel Rod Length
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