John Deere 310E Cranks but Won’t Start Often Traced to Fuel Shutoff Solenoid or Injection Pump Shaft Failure

[MikePhua]

The JD 310E and Its Reputation for Durability
The John Deere 310E backhoe loader was introduced in the mid-1990s as part of Deere’s evolution in the 310 series, which began in the 1970s. With a 4045D naturally aspirated diesel engine, mechanical injection system, and robust hydraulics, the 310E became a popular choice for municipalities, utility contractors, and rental fleets. Its reputation for reliability and ease of service made it a staple in North American fleets, with thousands sold before the transition to electronic control systems in later models.
Despite its mechanical simplicity, the 310E’s starting system can present challenges when fuel delivery is interrupted—especially after years of service or wiring degradation.
Symptoms of a No-Start Condition
Operators may encounter the following:

• Engine cranks normally but fails to fire
  
• Ether spray causes brief ignition, confirming compression and timing
  
• Fuel reaches the injection pump inlet
  
• No fuel delivery to injectors during cranking
  
• 12V power confirmed at the fuel shutoff solenoid
  

These symptoms suggest that the engine’s mechanical systems are intact, but fuel is not being delivered to the cylinders. The most common culprits are the fuel shutoff solenoid and the internal drive shaft of the injection pump.
Fuel Shutoff Solenoid Function and Testing
The fuel shutoff solenoid is mounted on the top of the injection pump and controls fuel flow by retracting a plunger when energized. If the solenoid fails to retract, fuel remains blocked even though the pump receives supply pressure.
Testing procedure:

• Turn key ON and listen for a click at the solenoid
  
• Disconnect the wire and manually apply 12V from a known good source
  
• Observe whether the solenoid clicks and retracts
  
• Measure resistance across solenoid terminals (should be between 10–40 ohms)
  
• Inspect wiring for corrosion or poor contact, especially near connectors
  

A technician in Alabama discovered that although 12V was present at the solenoid, the connection was too weak to energize the coil. After repairing a corroded splice one foot from the solenoid, the machine started reliably.
Injection Pump Shaft Failure and Internal Diagnosis
If the solenoid functions correctly but fuel still fails to reach the injectors, the issue may lie within the injection pump itself. The 4045D engine uses a rotary-type pump driven by a keyed shaft. In rare cases, the shaft may shear internally, causing the pump to stop rotating even though the engine cranks.
Diagnostic steps:

• Remove the fuel supply line at the pump inlet
  
• Fill the inlet fitting with diesel and crank the engine
  
• Observe whether the fuel level drops, indicating suction
  
• If no suction occurs, the pump is not turning
  
• Open the timing window on the pump to check gear movement
  
• Note that the shaft can break between the timing window and the drive gear
  

A mechanic in Wisconsin confirmed pump failure by observing no fuel draw during cranking. The pump was removed and found to have a sheared shaft, requiring full replacement.
Injector Line Crack Test and Fuel Delivery Confirmation
To confirm whether fuel reaches the injectors:

• Loosen one injector line at the cylinder head
  
• Crank the engine and observe for fuel spray or seepage
  
• If no fuel appears, delivery is blocked upstream
  
• If fuel is present but engine still won’t start, check injector spray pattern and compression
  

A restorer in Oklahoma used this method to verify that fuel was not reaching the injectors, leading him to investigate the pump internals.
Electrical Simplicity and Mechanical Reliability
Unlike later models, the 310E does not use an ECU or electronic sensors to control fuel delivery. The only electrical component required for starting is the fuel shutoff solenoid. This simplicity allows for straightforward troubleshooting but also means that mechanical failures—like a broken pump shaft—can halt operation without warning.
Best practices:

• Inspect solenoid wiring annually
  
• Replace solenoid every 2,000 hours or when resistance drifts
  
• Use dielectric grease on connectors to prevent corrosion
  
• Monitor fuel filter condition and change every 250 hours
  
• Keep spare solenoids and pump gaskets in field kits
  

A fleet manager in Texas implemented a preventive solenoid replacement schedule and reduced no-start incidents across his 310E units by 80%.
Conclusion
When a John Deere 310E cranks but won’t start, the most likely causes are a failed fuel shutoff solenoid or a broken injection pump shaft. With careful electrical testing, fuel flow observation, and mechanical inspection, technicians can isolate the fault and restore operation. In legacy diesel systems, fuel delivery is everything—and even a single wire or shaft can make the difference between silence and power.