The excavator has the fault of slow action, in which the boom action is the most obvious, and the engine speed decreases with load. Everything else of the hydraulic system and electrical is normal, and there is no alarm lamp and fault code.
1. Fault analysis
From the analysis of slow action and speed drop, it is most likely that the engine output power is insufficient. There are two reasons for the lack of engine power:
First, the intake pressure is insufficient due to the failure of the engine intake system. If the site conditions are too bad, the air intake system may fail.
Second, because of diesel oil circuit failure. If the oil is too poor, resulting in the failure of diesel oil circuit or fuel injection nozzle, the engine power will be insufficient.
2. Troubleshooting
1) First, check the air inlet system, check that the air filter is not blocked, check that the air inlet pipeline is not damaged and leaking, the supercharger works normally, and the intercooler is not abnormal. Remove the air filter and start the excavator. The fault is still the same. It is judged that it is not caused by the air inlet system.
2) Check the diesel oil circuit and find no blockage and air leakage. Replace the diesel filter element. It is found that the speed drop at low speed has improved, and there is no significant improvement at high speed. During the inspection, it was found that the quality of diesel was very poor, and the diesel filter element was blocked soon after replacement.
3) Then check and replace the fuel injector of the whole vehicle, start the excavator, the whole vehicle action returns to normal, and the load does not drop the speed.
After the above troubleshooting, it can be determined that the diesel oil is too poor, resulting in injector failure, insufficient engine power and speed loss.
3. How to identify diesel oil products
1) Look at the color
Normal diesel oil is colorless to light brown transparent liquid. If it is blackened or turbid, it is inferior diesel oil.
2) Smell
Normal diesel oil has a tasteless or light taste, while inferior diesel oil has a pungent smell.
3) Ask the seller
When purchasing, ask the Seller whether they have formal business license, fixed business place, etc. In order to ensure the normal operation of the excavator and reduce the occurrence of faults, it is necessary to add fuel from regular channels.
