Case 1835B Skid Steer Running Weird at Part Throttle

[MikePhua]

The user discussed an issue with the Case 1835B skid steer, where the machine runs erratically at part throttle. The engine experiences instability, power loss, or stalling when throttled to certain levels. This issue is often related to fuel supply, air intake, or problems in other engine systems, requiring thorough troubleshooting.
Troubleshooting Steps

1. Check the Fuel System
   Fuel supply issues are often the primary cause of erratic performance at part throttle. Begin by inspecting the fuel filter for any signs of clogging or contamination. A clogged filter restricts fuel flow, causing engine performance issues at lower throttle levels. Next, check the fuel pump and fuel lines for leaks, blockages, or damage.
   
2. Check the Air Filter
   Insufficient air supply can also affect engine performance at part throttle. Inspect the air filter to ensure it is not dirty or clogged. A clogged air filter limits airflow, resulting in a rich fuel mixture, which impacts engine performance. If the filter is dirty or damaged, replace it promptly.
   
3. Check the Throttle Control System
   If both the fuel and air systems appear to be functioning properly, the next step is to inspect the throttle control system. The mechanical linkage or electronic control components may be faulty, causing the throttle to not respond correctly. Check the throttle cable or the electronic throttle control unit to ensure smooth operation without any sticking or damage.
   
4. Inspect Engine Sensors and ECU (Electronic Control Unit)
   Modern skid steers are equipped with an ECU to manage engine functions. A faulty sensor or malfunctioning ECU can lead to inconsistent performance at different throttle levels. Use diagnostic tools to check the ECU for any fault codes and to verify sensor readings. If issues are found, address the problem by repairing or replacing the faulty components.
   

Solutions

1. Replace Fuel Filter and Check Fuel Pump
   If the issue is related to the fuel system, begin by replacing the fuel filter and inspecting the fuel pump for any issues. If the fuel pump is malfunctioning, replacement may be necessary.
   
2. Replace the Air Filter
   If the air filter is clogged or dirty, replace it with a new one to ensure proper airflow to the engine, allowing it to run smoothly.
   
3. Repair or Replace Throttle Control System
   If the throttle control system is malfunctioning, repair or replace the throttle cable or electronic control components. Ensure the throttle system responds properly to control the engine speed accurately.
   
4. Diagnose and Repair ECU Faults
   Use diagnostic tools to scan the ECU for fault codes, then repair or replace the faulty components based on the codes. This might include replacing damaged sensors or fixing the electronic control system to restore proper engine operation.
   

Conclusion
The Case 1835B skid steer’s erratic performance at part throttle can be caused by issues with the fuel system, air filter, throttle control, or the ECU. By systematically checking the fuel system, air filter, throttle controls, and ECU, the problem can be identified and resolved. Regular maintenance and inspection of these systems help prolong the machine’s life and improve operational efficiency.