Bobcat 843 Fuel Injection System Issues: Troubleshooting and Solutions

[MikePhua]

When it comes to maintaining and troubleshooting heavy equipment, one of the most common issues that operators and mechanics face is related to the fuel injection system. Specifically, users of the Bobcat 843 skid steer loader have reported issues with the fuel injection system that can cause poor performance, engine misfires, or even complete failure to start. This article will explore the common fuel injection-related problems, their causes, and how to troubleshoot and resolve them effectively.
Understanding the Fuel Injection System in Bobcat 843
The fuel injection system is responsible for delivering the correct amount of fuel to the engine's combustion chamber, ensuring smooth operation. A faulty fuel injection system can lead to various issues such as rough idling, reduced power, hard starting, or even engine failure. In the Bobcat 843, the system typically includes fuel injectors, fuel pumps, and a fuel filter, all of which must be in good working condition for optimal performance.
Common Fuel Injection Problems

1. Hard Starting:
   One of the most frequently reported issues is difficulty starting the engine. If the machine cranks but fails to start, or starts with difficulty, it may indicate an issue with fuel delivery.
   • Possible Causes:
     • Clogged fuel injectors
       
     • Malfunctioning fuel pump
       
     • Fuel filter blockages
       
     • Air in the fuel lines
       
   • Solution:
     • Check the fuel filter for clogs and replace it if necessary.
       
     • Inspect fuel lines for leaks or blockages.
       
     • Test the fuel pump to ensure it is providing adequate pressure.
       
     • Clean or replace fuel injectors if they are clogged.
       
2. Engine Misfire or Rough Idling:
   If the engine misfires or runs rough, it is often due to inconsistent fuel delivery. This can cause the machine to lose power or run inefficiently.
   • Possible Causes:
     • Dirty or malfunctioning fuel injectors
       
     • Incorrect fuel mixture
       
     • Faulty fuel pressure regulator
       
   • Solution:
     • Clean or replace the fuel injectors.
       
     • Check the fuel pressure and regulator to ensure proper fuel flow.
       
     • Ensure the fuel quality is good and free from contaminants.
       
3. Low Power or Lack of Acceleration:
   A loss of power, especially when attempting to accelerate, can also be a sign of fuel delivery issues, particularly if the injectors are not providing the correct amount of fuel.
   • Possible Causes:
     • Fuel injectors not spraying properly
       
     • Low fuel pressure
       
     • Fuel system leaks
       
   • Solution:
     • Inspect the fuel injectors for proper operation and replace if necessary.
       
     • Check for any fuel system leaks, including hoses, lines, and the fuel tank.
       
     • Test the fuel pressure and replace the fuel pump if the pressure is too low.
       
4. Fuel Contamination:
   Contaminated fuel is a serious problem and can lead to a variety of engine issues, including poor performance and damage to the fuel system.
   • Possible Causes:
     • Water or dirt in the fuel
       
     • Poor fuel quality
       
     • Old or stale fuel
       
   • Solution:
     • Drain the fuel tank and replace with fresh, clean fuel.
       
     • Replace the fuel filter to ensure it’s not clogged with debris or water.
       
     • Clean the fuel lines to remove any dirt or contaminants.
       

Steps to Troubleshoot Fuel Injection System Issues

1. Inspect Fuel Filter and Fuel Lines:
   The first step in troubleshooting fuel injection issues is to inspect the fuel filter and fuel lines for any signs of clogs, damage, or leaks. A clogged fuel filter can restrict fuel flow, leading to poor performance.
   
2. Check Fuel Pump Pressure:
   A malfunctioning fuel pump can cause low fuel pressure, which can lead to poor engine performance. Check the fuel pump for proper pressure and ensure it's delivering fuel efficiently.
   
3. Test Fuel Injectors:
   Fuel injectors are critical for delivering the correct amount of fuel to the engine. If the injectors are clogged or malfunctioning, they should be cleaned or replaced. You can test them using a fuel injector cleaning kit or a professional diagnostic tool.
   
4. Examine Electrical Components:
   Electrical components such as the fuel pressure regulator, wiring harness, and sensors can sometimes cause fuel injection problems. Inspect the wiring for any signs of wear or loose connections. If necessary, test the sensors to ensure they are sending the correct signals.
   
5. Check for Air in the Fuel Lines:
   Air in the fuel lines can prevent proper fuel delivery. Bleed the fuel lines to remove any trapped air, and ensure the fuel tank is not too low.
   

Preventative Maintenance Tips for the Fuel System

• Regularly replace the fuel filter to prevent contaminants from reaching the injectors.
  
• Use high-quality, clean fuel to avoid clogging the injectors and fuel lines.
  
• Periodically inspect the fuel system for leaks, cracks, or other signs of wear.
  
• Perform routine cleaning and maintenance on the fuel injectors to ensure they are functioning properly.
  

Conclusion
The fuel injection system in the Bobcat 843 is crucial for maintaining the performance and reliability of the machine. Common issues such as hard starting, engine misfires, low power, and fuel contamination can often be traced back to problems with the fuel delivery system. By following a systematic approach to troubleshooting and maintaining the fuel system, operators can keep their Bobcat 843 running smoothly and avoid costly repairs. Regular inspections, timely repairs, and the use of clean, high-quality fuel can help prevent many of the common fuel injection problems associated with this machine.