TM 5-3810-300-24&P-3
15.2 Trouble Shooting (Engine)
Chart 3
ABNORMAL ENGINE OPERATION
SUGGESTED REMEDY
1
Check the engine coolant temperature gage and, if
Check the compression pressures (consult the Hard
the temperature does not reach 160 to 185 F while the
Starting chart).
engine is operating, consult the Abnormal Engine
Coolant Temperature chart.
9
Incorrect operation of the engine may result in
excessive loads on the engine. Operate the engine
2
Check engine fuel spill back and if the return is less
according to the approved procedures outlined in the
than specified, consult the No Fuel or Insufficient Fuel
Drivers Handbook.
chart.
10
Refer to Item 13 on Chart 4.
3
Check the injector timing and the position of the
injector racks. If the engine was not tuned correctly,
11 Check the ambient air temperature. A power
perform an engine tune-up. Erratic engine operation
may also be caused by leaking injector spray tips.
depending upon injector size, for each 10 F.
Replace the faulty injectors.
temperature rise above 90 F will occur. Relocate the
4
Check the compression pressures within the
engine air intake to provide a cooler source of air.
cylinders and consult the Hard Starting chart if
compression pressures are low.
12 Engines lose horsepower with increase in altitude.
The percentage of power loss is governed by the altitude
5
Erratic engine operation may be caused by
at which the engine is operating.
governor-to-injector operating linkage bind or by faulty
engine tune-up Perform the appropriate engine tune-up
13 Fill oil bath air cleaners to the proper level with the
procedure as outlined for the particular governor used.
same grade and viscosity lubricating oil that is used in
the engine.
6
Perform an engine tune-up if performance is not
satisfactory.
Clean the air box and drain tubes to prevent
accumulations that may be picked up by the air stream
Check the engine gear train timing. An improperly timed
and enter the engine's cylinders.
gear train will result in a loss of power due to the valves
and injectors being actuated at the wrong time in the
Inspect the blower oil seals by removing the air inlet
engine's operating cycle.
housing and watching through the blower inlet for oil
radiating away from the blower rotor shaft oil seals while
7
Perform a Fuel Flow Test and, if less than the
the engine is running. If oil is passing through the seals,
specified fuel is returning to the fuel tank, consult the No
overhaul the blower.
Fuel or Insufficient Fuel chart.
Check for a defective blower-to-block gasket. Replace
8
Check for damaged or dirty air cleaners and clean,
the gasket, if necessary.
repair or replace damaged parts.
14
Refer to Item I of this chart.
Remove the air box covers and inspect the cylinder liner
ports. Clean the ports if they are over 50% plugged.
15 Check injector timing and the position of each
injector rack. Perform an engine tune-up, if necessary. If
Check for blower air intake obstruction or high exhaust
the engine is correctly tuned, the erratic operation may
back pressure. Clean, repair or replace faulty parts.
be caused by an injector check valve leaking, spray tip
holes enlarged or a broken spray tip. Replace faulty
injectors.
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