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How to Deal With Cummins Diesel Generator Set is Unstable After Starting

Oct. 15, 2021

What to do if the Cummins diesel generator set becomes unstable after starting? Loosen the high-pressure oil pump bleed screw, press the hand oil pump, and purge the air in the oil circuit. Fasten the oil return screws of the high and low pressure oil pipes of the Cummins diesel generator set. And after starting the Cummins diesel generator set, the speed was increased to about 1000r/min, and it was investigated whether the speed was stable, but the sound of the Cummins diesel generator set was still unstable and the fault was not eliminated. Check the oil gauge in the oil pan of the Cummins diesel generator set to investigate whether the oil viscosity is too low or the amount of oil is too much, so that the oil enters the incineration chamber and evaporates into oil and gas that is not incinerated and discharged from the exhaust pipe.


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However, it was found that the quality and quantity of the engine oil complied with the oil rules of Cummins diesel generator sets. At the same time, the high-pressure oil pipes of the upper four cylinders of the high-pressure oil pump were cut off one by one. It was found that the blue smoke disappeared after the third cylinder was disconnected. After the shutdown, the third-cylinder injector was disassembled, and the fuel injection pressure test was performed on the injector. The results found that the third-cylinder injector pair had a dripping appearance and the amount was small, and one was drawn from a thin wire. The thin copper wire close to the diameter of the nozzle hole unclogs the nozzle hole.


After dredging and re-testing, it was found that the nozzle assembly sprayed normally, and then the injector was installed and the Cummins diesel generator set was started. It was found that the blue smoke did not appear to be exhausted, but the speed was still unstable. Finally, remove the high-pressure oil pump assembly and check the internal skills of the governor. It is found that the conditioning rack is not sensitive to movement. After repairing, adjusting and installing, start the Cummins diesel generator set to a speed of about 700r/min, and investigate whether the operation is stable. No abnormality is found during the inspection, and the fault will be removed.


Guangxi Dingbo Generator Set Manufacturing Co.,Ltd., is one of the earliest manufacturers of generators and diesel generator sets in China. The company has a registered capital of 218.88 million yuan. The company covers an area of 86,000 square meters and a building area of 55,000 square meters. There are more than 660 employees, including 456 professional technicians and 106 senior technicians. It has 46 sales and service outlets nationwide. The main products are diesel engines, generator sets, and diesel generators, providing users with a one-stop service of design, supply, debugging and maintenance at any time. Starlight has always insisted on using first-class talents, building first-class enterprises, manufacturing first-class products, creating first-class services, and making every effort to build a first-class domestic enterprise. If any question please feel free to visit our website https://www.dieselgeneratortech.com/ or send email to sales@dieselgeneratortech.com.

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