TM 9-4940-568-34
2-9
Table 2-3. Engine Troubleshooting (CONT).
Malfunction
Test or Inspection
Corrective Action
16. ENGINE RUNS ROUGH OR IS MISFIRING.
Valve adjustment is incorrect.
Check for a bent push rod and adjust valves (TM 9-4940-568-20).
Injection pump timing is incorrectly adjusted.
Check top dead center (TDC) (Para 7-9).
Check and adjust injection pump timing (Para 5-19).
Compression in one or more cylinders is low.
Perform a compression check and repair as required (Para 5-8).
Injectors are malfunctioning.
Check and replace injectors (TM 9-4940-568-20).
Injection pump (delivery valves) is defective.
Replace fuel injection pump (Para 5-17).
Camshaft out of time.
Check and correct gear train timing alignment (Para 7-7).
Camshaft or tappets are damaged.
Inspect camshaft and tappets (Para 7-7).
17. ENGINE RPM WILL NOT REACH RATED SPEED.
Fuel injection pump is malfunctioning.
Replace fuel injection pump (Para 5-17).
18. ENGINE POWER OUTPUT IS LOW.
Injectors worn or malfunctioning.
Check injectors (TM 9-4940-568-20).
Fuel injection pump timing incorrect.
Adjust fuel injection pump timing (Para 5-18).
Fuel injection pump malfunctioning.
Replace fuel injection pump (Para 5-16).
Engine compression low.
Replace engine (Para 5-4).
