How to Deal with The Leakage of Diesel Generator Fuel System?

The fuel injector is a key component of the diesel generator fuel system. Internal leakage of the fuel injector is generally difficult to see with the naked eye. When it is found that the diesel generator cannot be started, the power is weak, and the oil circuit has air or not, it will sometimes automatically turn off, and the fuel injection pump housing or oil pan rises abnormally, which can be diagnosed as an internal leakage of the fuel injection pump. The 6 detailed leak sites of the diesel generator injector are as follows:

1. There is leakage at the assembly shoulder of the plunger sleeve. There is no sealing gasket between the large cylindrical shoulder of the plunger sleeve of the piston nozzle and the upper body of the pump, and the sealing is realized by the fine machining of the two joint surfaces. It is an annular, extremely small sealing surface. The obvious squeezing marks that appear at this time will cause a large amount of diesel leakage, which will make the diesel generator unable to work normally. Sometimes it can barely run at low speed, but air will be sucked in when the speed rises. The main reason for the extrusion marks on the shoulder of the piston sleeve installation is that the torque of the oil pressure adjuster seat is too large, and the fluctuating stress of the high-pressure diesel oil during operation will also accelerate the fatigue and strain.

2. The leakage problem of the gap between the plunger and the plunger sleeve. The fit between the piston and the plunger sleeve is inherently precise, with a clearance of only 0.002~0.003 mm. If selected and ground, its surface roughness accuracy is very high. During work, if the diesel oil contains impurities and moisture, it will cause damage or corrosion of the plunger coupler, the gap will increase, the diesel oil will leak, and it will not cause high pressure to the diesel oil.

3. The screw positioned by the plunger sleeve leaks oil. There is a pure copper pad under the set screw of the plunger sleeve, and its specific function is to seal. If this small gasket assembly leaks or fluffs or cracks, the diesel fuel in the plunger sleeve will leak from the set screw.

4. The oil outlet valve leaks. When the pure copper (or nylon) gasket between the high pressure oil chamber on the oil outlet valve and the large end face of the oil outlet valve seat is broken and deformed, or when the oil outlet valve seat is not tightened, the high pressure oil chamber on the oil outlet valve and the bottom The low-pressure oil chamber connection of the diesel generator causes the fuel injection pump of the diesel generator to fail to produce high-pressure diesel.

5. The leakage problem of the oil return relief valve. The multi-cylinder fuel injector is provided with an oil return overflow valve, whose function is to keep the diesel pressure in the horizontal oil passage of the upper body of the fuel injector above 150kPa. For example, the oil return relief valve and valve seat are worn, rusted, there is garbage on the door, or there is an oil return condition, reduce the diesel pressure at the oil inlet of the plunger, and suck air into the injector, so that the diesel generator cannot work, Automatically shut off.

6. Oil seepage between the push rod of the oil pump and the casing. If the plunger oil pump push rod and bushing are worn too much or the push rod seal is damaged, the oil discharge will be greatly increased. If the oil drain hole is blocked, this part of the diesel oil will flow into the oil passage of the fuel injection nozzle.

Dingbo Power was founded in 2006 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to sales@dieselgeneratortech.com we will pay highly attention on your question.