Since all the
injector racks are connected to the fuel control tube and then to the governor by the fuel
rod or rods, they must be set correctly. This ensures that they are equally related to the
governor. Their positions determine the amount of fuel that will be injected into the
individual cylinders, ensuring equal distribution of the load. Failure to set the racks
properly will result in poor performance and a lack-of-power complaint.
inner and outer adjusting screws on the rack control lever (fig. 5-27)
equalizes the injectors. This is a rather delicate adjustment. and it may be necessary to
make these adjustments several times before the engine operates just right.
the amount of fuel injected, loosen the outer adjusting screw and tighten the inner
adjusting screw, thereby moving the control rack inward. To decrease fuel injection,
loosen the inner adjusting screw slightly and tighten the outer adjusting screw which
moves the control rack outward. In making the operating adjustments, never turn the
adjusting screws more than one-fourth turn at a time; for if one injector is adjusted too
far out of line with the others, it will prevent the full travel of the racks and reduce
the maximum power to the engine.
For exact procedures for adjusting the
injector rack control levers, refer to the manufacturers service manual.
smoother engine operation can be obtained by making slight changes to the adjustments
after the engine is warmed to operating temperature (above 140°F). For example, one
cylinder may not be carrying its share of the load as indicated by a comparatively cooler
cylinder. Therefore, the control rack should be adjusted for more fuel. A slight knocking
noise from another cylinder would indicate an adjustment for slightly less fuel.
Do not attempt
to obtain a smooth running engine by changing control-rack settings without first timing
and equalizing injection in the recommended manner.