New Holland 575E Fuel System Problem

[MikePhua]

Machine Overview
The New Holland 575E is a reliable tractor loader backhoe known for its versatility in construction, agriculture, and utility work. Powered by a 4-cylinder diesel engine producing roughly 85 hp, the 575E features hydraulic wet disc brakes, mechanical differential locks, and a 4-speed power shuttle transmission. The fuel system typically includes a fuel tank capacity of 28 gallons, a fuel lift pump, filters, and an injection pump delivering fuel to the engine.
Fuel System Symptoms and Problem
The unit is exhibiting symptoms of running out of fuel under load although it idles well. The engine starts fine but gradually loses power and dies after about 30 seconds under load, then restarts easily after sitting. Attempts to fix this included:

• Replacing the fuel lift pump twice with identical results
  
• Checking and clearing the fuel line from the tank with no improvement
  
• Installing an additional electric fuel pump before the factory pump with no change
  
• Ensuring all filters are clean and replaced recently
  
• Air cleaner in good condition
  

Possible Causes

• Failing Injection Pump: The injection pump may not be delivering enough fuel under high demand even if the lift pumps are working properly.
  
• Fuel Line or Injector Blockage: Partial clogging downstream causing restricted fuel flow under load.
  
• Air Leak in Fuel System: Air entering through loose fittings causes fuel starvation under load.
  
• Fuel Metering Issues: Injector timing or metering valves inside the injection pump may be faulty.
  
• Fuel Pump Drive or Control Problems: Mechanical or electrical faults affecting pump speed or pressure.
  
• High Altitude Effects: Being at a lodge 10,000 ft above sea level could affect fuel combustion if air-fuel mixture is not properly adjusted.
  

Recommendations

• Perform a thorough inspection of the injection pump and injectors for wear or damage.
  
• Conduct fuel pressure and volume tests on the injection pump output under running load.
  
• Check all fuel lines, clamps, and fittings for leaks allowing air into the system.
  
• Consider professional injection pump diagnosis or rebuild since these units are costly but critical.
  
• Adjust engine tuning for high-altitude operation which requires leaner combustion management.
  
• Utilize a fuel additive to improve lubrication and fuel stability.
  
• If remote and unable to trailer, a mobile technician experienced in diesel fuel systems may be necessary on site.
  

Terminology

• Injection Pump: Component delivering precise amounts of fuel to engine cylinders at high pressure.
  
• Fuel Lift Pump: Low-pressure pump moving fuel from tank to injection pump.
  
• Injector: Nozzle injecting fuel as a fine mist into combustion chambers.
  
• Load: Operating condition when the engine is under mechanical strain such as digging or towing.
  
• Air Leak: Entry of air into fuel lines causing pressure drops and fuel starvation.
  

A Real-World Note
A similar case happened to an operator working at high altitude who experienced power loss under load on a diesel backhoe. The problem was traced to faulty injector pump internal seals causing slip under increased fuel demand. After overhaul and altitude adjustment, the engine ran smoothly at idle and load. This highlights the importance of shop-level diagnostic tools and altitude-aware tuning for remote operations.
Conclusion
Fuel starvation issues on the New Holland 575E, especially under load and at altitude, often point towards injection pump or fuel metering problems even if lift pumps and filters are clean. Careful testing and inspection of the injection pump and fuel system is crucial before considering costly replacements. Proper high-altitude adjustments and expert diagnostics maximize chances of restoring reliable engine performance when remote repair options are limited.