Main Engine RPM is unstable. Uneven firing in cylinder units observed. Sometimes sudden stop of ME experienced. What could be the cause of this?

07 Jul '17, 20:11

July 7, 2017, 8:11 p.m.
KnowledgeBase's gravatar image


In the case of RPM hunting/fluctuation or cylinder misfiring check folowing:

  • a) The fuel pressure is too low before the injection pump. Filters may be dirty or fuel circulating/booster pump defective.
  • b) The fuel temperature before the injection pump is too low or too high. For proper atomization, the fuel temperature and hence viscosity must be in working range according to its grade.
  • c) The air from the fuel pipes is poorly discharged. The fuel system is not properly primed after maintenance. Bleed out the remaining air.
  • d) Fuel contains water. Poor purification and filtrations are the root cause.
  • e) Leaks or defects in the fuel injection system. Injector or fuel injection pumps need an overhaul.
  • f) Temporary activation of the automatic shut-off device (protection). Check if all engine critical parameters (LO pressure, FW cooling temperature and pressure) in working range and not activate the slowdown or shutdown. Chek for defective sensors.

If the engine suddenly stops, check following:

  • a) Lack of fuel supply: tank empty, valve is closed, the fuel filter is dirty.
  • b) The oil or water pressure is too low, water temperature too high, the protection has tripped. See above, bring parameter to the normal working range, check sensors.
  • c) The over-speed protection was activated. Rectify the engine overspeeding, check/clean/replace RPM pick-up sensors.
  • d) Failure in the stop pneumatic cylinder or servo.
  • e) Defect (leakage) of control air pipes.
  • f) Failure of the governor.
  • g) The control lever at the local post is not in the correct position.
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07 Jul '17, 20:33

July 7, 2017, 8:33 p.m.
SeamenExchangeExpert's gravatar image

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