TM 9-2330-356-14
Table 4-9. Unit Troubleshooting (Con`t).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE (Con't)
19. ENGINE SPEED IS NOT CONSTANT (HUNTING, LOSS OF CONTROL).
Step 1.
If defective, replace manifold heater or lead.
(Defective fuel system) Check fuel lines for leaks. Test for non-functioning electric fuel pumps
Step 2.
a. Tighten all connections and replace or repair any damaged fuel lines.
b. Replace fuel pump, if defective, or repair or replace fuel transfer pump wiring
Perform all steps under Malfunction 20, HIGH OR LOW ENG/NE SPEEDS.
Step 3.
20. HIGH OR LOW ENGINE SPEEDS.
Step 1.
Check for loose or disconnected throttle linkage (para 4-75).
Connect throttle linkage.
Check for binding in linkage.
Step 2.
Clean and lubricate linkage.
Step 3.
Adjust throttle linkage.
Step 4.
Adjust governor sensitivity.
21. BLACK SMOKE EXHAUST OR EXCESSIVE FUEL CONSUMPTION.
NOTE
The brown or black color in the exhaust is from minute solid particles of pure carbon. A darker
exhaust Indicates a higher carbon content. The exhaust color may vary from alight gray haze to a
brown or black, which indicates incomplete combustion. Since combustion is never absolutely
complete, the exhaust gases will never be invisible, but an increase may indicate trouble,
especially if there is no apparent change in engine conditions.
Check for engine overload.
Step 1.
Reduce fuel dispensing rate or increase engine speed.
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