Diagnosing Fuel Delivery and Starting Issues in the 2006 John Deere CT322

[MikePhua]

John Deere CT322 Overview and Market Legacy
The John Deere CT322 is a compact track loader introduced in the mid-2000s as part of Deere’s push into the CTL market. With an operating weight of approximately 9,500 lbs and a 66 hp diesel engine, the CT322 was designed for grading, excavation, and material handling in tight spaces. Deere’s reputation for durability and parts support helped the CT322 gain traction among contractors and rental fleets. Though production has since shifted to newer G-series models, the CT322 remains a workhorse in many operations.
Terminology Clarification
- Lift Pump / Transfer Pump: A low-pressure pump that supplies fuel from the tank to the injection system. Often confused with the high-pressure injection pump. - Check Valve: A one-way valve that prevents fuel from draining back into the tank when the engine is off. - Governor Rod: A mechanical linkage that regulates engine speed based on load and throttle input.
Symptoms of Fuel System Failure
Owners of the CT322 have reported hard starting after the machine sits idle for several days. The engine requires extensive cranking and manual priming to start, and once running, it surges erratically. These symptoms typically point to fuel delivery issues, including:

• Fuel draining back into the tank due to a failed check valve
  
• Air entering the system through loose fittings or degraded seals
  
• Weak or malfunctioning lift pump unable to maintain pressure
  
• Faulty governor linkage preventing proper fuel regulation
  

In one Missouri-based case, the machine ran perfectly in the fall but developed issues after sitting unused through winter. Despite replacing filters and performing routine maintenance, the problem persisted until deeper fuel system diagnostics were performed.
Step-by-Step Diagnostic Strategy
To resolve these issues, technicians should follow a structured approach:
- Inspect the hand primer pump and associated check valve. If fuel drains back after shutdown, the check valve may be clogged or stuck open. - Test the lift pump (also referred to as the transfer pump). If it fails to maintain pressure, replace it with a compatible unit—typically priced around $80. - Check for air leaks at hose connections, especially near the fuel/water separator and filter housing. - Inspect the governor rod under the valve cover. If it’s disconnected or jammed, fuel delivery will be erratic regardless of pump performance. - Verify injector function. If injectors are clogged or damaged, they may require replacement or cleaning.
Real-World Repair Outcomes
In one documented case, the lift pump was replaced, but the machine still failed to start. Deere technicians ultimately discovered that the governor rod was disconnected, preventing fuel regulation. Once reconnected and injectors replaced, the machine returned to normal operation.
Another technician recommended replacing the check valve located on the left side of the engine near the flywheel. This barbed fitting maintains residual pressure in the fuel rail. If it fails, fuel drains back, causing hard starts and extended cranking.
Preventive Maintenance Recommendations
To avoid future fuel system failures:

• Replace fuel filters every 250 hours or annually
  
• Inspect and clean the check valve during seasonal maintenance
  
• Use fuel stabilizer if the machine will sit idle for extended periods
  
• Keep the tank full during storage to reduce condensation and microbial growth
  
• Periodically test lift pump pressure and flow rate
  

Conclusion
The 2006 John Deere CT322 is a reliable compact track loader, but like many diesel machines, it’s vulnerable to fuel system degradation over time. Hard starting, surging, and inconsistent throttle response are often linked to check valve failure, lift pump wear, or mechanical linkage issues. With methodical diagnostics and targeted repairs, these problems can be resolved without major overhaul. For owners and fleet managers, understanding the nuances of the CT322’s fuel system is key to keeping this machine productive and dependable year-round.