Figure 3-41.—Possible causes of insufficient power in an engine.
be no apparent resistance to the motion of the rack if the
return springs and linkage are disconnected. A stuck
control rack may be caused by the plunger’s sticking in
the pump barrel; dirt in the rack mechanism; damage to
the rack, sleeve, or gear; or improper assembly of the
injector pump.
If the rack sticks or jams, you must determine the
cause and replace any damaged parts. If sticking is due
to dirt, thoroughly clean all the parts to correct the
trouble. You can avoid errors in assembly by carefully
studying the assembly drawings and instructions.
Leakage of Fuel Oil
Leakage of fuel oil from the injectors may cause an
engine to continue to operate when you attempt to shut
it down. Regardless of the type of fuel system, the results
of internal leakage from injection equipment are, in
general, somewhat the same. Injector leakage will cause
unsatisfactory engine operation because of the
excessive amount of fuel entering the cylinder. Leakage
may also cause detonation, crankcase dilution, smoky
exhaust, loss of power, and excessive carbon formation
on the spray tips of nozzles and other surfaces of the
combustion chamber.
Accumulation of Lube Oil
Another trouble that may prevent you from stopping
an engine is accumulation of lube oil in the intake air
passages-manifold or air box. Such an accumulation
creates an extremely dangerous condition. You can
detect excess oil by removing the inspection plates on
the covers and examining the air box and manifold. If
you discover oil, remove it and perform the necessary
3-37
