The excavator cannot start and makes abnormal noises

Customer AbrandThe excavator emits white smoke and has difficulty starting, and there is abnormal noise during operation;

Analyze the reasons:

A company personnel first arrived at the site and inspected the diesel and diesel filter elements and air filters, which were in good condition. At the beginning of the start-up, they sensed three areas with poor heat by hand. Later, they removed the diesel pump and found cracks on the outer ring of the vane pump;
The machine has a significant malfunction and requires a laptop computer for diagnosis of the engine ECU control system. Therefore, our office personnel went to the site again and first replaced the diesel pump. Then, the computer diagnosed the fault situation. During the cylinder cut test, it was found that three fuel injectors had poor fuel injection. At this time, the engine emitted white smoke and made a 'click, click' sound, and it was still difficult to start;
C subsequently replaced three fuel injectors, entered QR codes, and learned about the pump. During the initial operation, white smoke still emitted, but after running for a period of time, the white smoke disappeared. However, at this time, the engine also made a 'stuck' sound, and after running at high and low speeds and various actions, there was still a sound. We had to report this situation to the relevant personnel of the company, which may be new or oldFuel injectorThe mismatch is related, and the company has decided to replace all fuel injectors

Solution:

1. After replacing all fuel injectors, there is still a 'stuck' sound when starting and running, which is significantly louder compared to other excavators. Adjustments A, B, and C have been made but there is no improvement. After unplugging the SCV valve plug, there is no sound, but there is still a front abnormal sound when replacing the normal SCV valve twice;
2. All aspects of the computer diagnosis were normal, but it was suspected that there was a malfunction with the ECU computer. After replacing the computer, the sound was reduced, and the company reported that it was not related to the ECU. Therefore, it was decided to save the data of the excavator's' performance ',' analysis', 'cylinder compensation', etc. and send it back to the company. After completing the data testing, the machine returned to normal;
3. Based on the above situations, it is possible that there is air in the common rail causing noise after replacing the fuel injector, or that the new fuel injector has been running well for a period of time