Because the fuel injector works under high temperature and high pressure for a long time, it is easy to cause faults such as loose sealing, oil dripping and poor atomization. These faults may cause serious faults such as black smoke, insufficient power, abnormal noise of combustion system, cylinder pulling and piston top burning. However, in the field troubleshooting, how to confirm that the above faults are caused by the problem of fuel injector is the key to troubleshooting. Based on many years of practical work experience, the manufacturer of gas generator set has obtained the following basic methods to confirm that the fuel injector has quality problems:

１、首先直接觀察燃氣機的排煙情況，如果噴油器存在上述問題，柴油機排煙應該是：起動時冒白煙、全負荷工作時冒黑煙并伴隨有功率不足等問題。

1. First, directly observe the smoke exhaust of the gas engine. If the fuel injector has the above problems, the smoke exhaust of the diesel engine should be: white smoke when starting, black smoke when working at full load, accompanied by insufficient power and so on.

２、單缸滅火法：

2. Single cylinder fire extinguishing method:

起動燃氣機中低速運轉，然后逐缸松開高壓油管，當松開某缸高壓油管后，柴油機排氣煙色有明顯變化時，則說明該缸噴油器或柱塞／出油閥有問題。

Start the gas engine at medium and low speed, and then loosen the high-pressure oil pipe cylinder by cylinder. When the high-pressure oil pipe of a cylinder is loosened and the exhaust smoke color of the diesel engine changes significantly, it indicates that there is a problem with the injector or plunger / outlet valve of the cylinder.

３、直接觀察法

3. Direct observation method

拆下排氣管，起動燃氣機低速運轉，可以直接看出某缸排氣煙色不正常，即可初步判斷該缸噴油器或是柱塞／出油閥有問題。

Remove the exhaust pipe and start the gas engine to run at low speed. It can be directly seen that the exhaust smoke color of a cylinder is abnormal, and it can be preliminarily judged that there is a problem with the injector or plunger / outlet valve of the cylinder.

４、在確認某缸噴油器或柱塞／出油閥有問題后，可以取出該缸噴油器，在噴油器試驗器上確認該噴油器是否有問題。

4. After confirming that there is a problem with the injector or plunger / outlet valve of a cylinder, take out the injector of the cylinder and confirm whether there is a problem with the injector on the injector tester.

５、如果經過試驗確認噴油器有問題，則必須按要求修復或更換噴油器（嘴）。

5. If there is a problem with the fuel injector after the test, the fuel injector (nozzle) must be repaired or replaced as required.

６、如果現場附近沒有噴油器試驗器，作為臨時措施，可以在柴油機上檢查一下噴油器是否有問題。具體做法是：將排氣煙度相反的兩個缸的噴油器調換使用，起動燃氣機并觀察排氣煙色，如果調換使用后，原來不冒煙的缸煙度增大，則說明該噴油器有問題。如果兩個缸的煙度都增大，則說明該缸（原來冒黑煙）的柱塞／出油閥可能也有問題。、

6. If there is no injector tester near the site, as a temporary measure, check whether there is a problem with the injector on the diesel engine. The specific method is: exchange the fuel injectors of two cylinders with opposite exhaust smoke, start the gas engine and observe the exhaust smoke color. If the smoke of the cylinder that did not smoke increases after exchange, it indicates that there is a problem with the fuel injector. If the smoke of both cylinders increases, there may also be a problem with the plunger / outlet valve of the cylinder (originally emitting black smoke)

７、如果試驗確認噴油器沒有問題后，則需要進一步檢查噴油泵。

7. If the test confirms that there is no problem with the fuel injector, further check the professional fuel injection pump.