Takeuchi TB138FR Excavator Losing Engine RPM When Digging

[MikePhua]

Users have reported that the Takeuchi TB138FR excavator experiences a drop in engine RPM during digging operations. This issue can significantly affect the performance and efficiency of the excavator. This article explores the possible causes and provides troubleshooting and solutions.
Possible Causes

1. Excessive Load
   When the excavator is under heavy load, the engine may reduce RPM to protect itself from overloading. This is common during high-load operations, as the engine automatically lowers the RPM to avoid damage.
   
2. Fuel Supply Issues
   A clogged fuel filter or malfunctioning fuel pump can cause unstable fuel supply, leading to fluctuating engine RPM. It’s essential to inspect the fuel system to ensure there are no blockages or issues with fuel delivery.
   
3. Clogged Air Filter
   A clogged air filter reduces airflow to the engine, preventing it from getting enough air for combustion, which can cause the engine RPM to drop. Regular inspection and cleaning of the air filter are necessary for optimal engine performance.
   
4. Engine Control Module (ECM) Malfunction
   The ECM regulates various engine parameters. If the ECM malfunctions, it may fail to adjust the engine settings properly, affecting the RPM. Using diagnostic tools to check for fault codes can help determine if the ECM is functioning correctly.
   
5. Hydraulic System Issues
   Problems in the hydraulic system can also impact the engine RPM, especially during heavy-duty operations like digging and lifting. If hydraulic pressure is too high or there are leaks in the system, the engine’s RPM may decrease.
   

Troubleshooting and Solutions

1. Check the Load
   Ensure that the excavator is not overloaded during digging. Avoid operating under extreme conditions, such as steep slopes or in very hard soil. Adjust the operation technique to avoid excessive strain on the engine.
   
2. Inspect the Fuel System
   Make sure the fuel filter is clean and not clogged. Check the fuel pump to ensure proper fuel supply to the engine. Replace any faulty components if necessary.
   
3. Check the Air Filter
   Regularly inspect the air filter, particularly in dusty environments. Clean or replace the air filter as needed to ensure the engine is receiving an adequate supply of air for combustion.
   
4. Use Diagnostic Tools to Check the ECM
   Use a diagnostic tool to read the fault codes from the ECM. If the ECM is malfunctioning, it may need to be repaired or replaced.
   
5. Inspect the Hydraulic System
   Check the hydraulic system’s pressure settings to ensure they are within the recommended range. Look for any leaks and ensure the hydraulic fluid is at the proper level and quality.
   

Conclusion
The loss of engine RPM in the Takeuchi TB138FR excavator during digging can be caused by several factors, including excessive load, fuel system issues, a clogged air filter, ECM malfunctions, and hydraulic system problems. By systematically troubleshooting each potential cause, operators can quickly resolve the issue and restore optimal performance. If the problem persists after following these steps, it is advisable to consult a professional technician for further diagnosis.