Solutions for Unstable Working of Generator Set After Starting

Jul. 06, 2021

Recently some users ask Dingbo Power why generator set works unstably after starting and how to deal with the problem, now Dingbo Power will tell you.


When your generator set working unstably after starting, it maybe have below problem, and we should find out the main reason, then solve it according to different reasons.


A. The governor cannot reach a lower speed.


Solutions: cut off the high-pressure oil pipes of the upper four cylinders of the high-pressure oil pump one by one, and the results showed that the blue smoke disappeared after the third cylinder was cut off. After shutdown, disassembly the third cylinder injector, and test the injection pressure. The results showed that the third cylinder injector had little oil dripping.


B. The bad working of each cylinder of the generator set results in different compression pressure of each cylinder.


Solutions: check the oil gauge in the diesel oil pan to see if the oil viscosity is too low or the amount of oil is too much, so that the oil enters the combustion chamber and evaporates into oil gas, which is not burned and discharged from the exhaust pipe. However, it is found that the quality and quantity of engine oil meet the requirements of diesel engine.


C. The internal speed governing spring of the governor is weakened, which changes the speed regulating performance.


Solutions: after starting the generator set, increase the speed to about 1000r/min, observe whether the speed is stable, but hear the sound of generating set is still unstable, the fault has not been eliminated.


Diesel generating set

D. There is air or water in the fuel supply system or the fuel supply is not smooth.  

Solutions: loosen the high-pressure oil pump bleed screw, press the hand oil pump, remove the air in the oil circuit.


E. The oil supply quantity of each plunger in the high pressure oil pump is more related.


Solutions: tighten the oil return screw of high and low pressure oil pipes of diesel engine.


F. The governor speed cannot reach the rated speed.

Solutions: remove the high-pressure oil pump assembly and conduct technical inspection on the governor. It is found that the movement of the adjusting gear rod is not flexible. After repair, adjustment and assembly, start the diesel engine until the speed reaches about 700r/min, and observe whether the diesel engine works smoothly. 


G. The internal rotation parts of the governor are not balanced or the clearance is too large.

Solutions: take out a thin copper wire from a thin wire, which is close to the diameter of the spray hole, and dredge the spray hole. After dredging and testing again, it is found that the spray nozzle is normal, and then the fuel injector is assembled to start the diesel engine. The phenomenon of blue smoke is disappeared, but the speed of the diesel engine is still unstable.


All above operations should be done by a professional engineer to ensure safety. If you still have something not clear or do not know how to deal with the problem, can contact Dingbo Power company, we will try our best to help you. Or if you are interested in generator set, please call us by phone +86 134 8102 4441 ( same as WeChat ID).

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