Fuel system
High-pressure common rail (HPCR) (9.0 L)
 
Right-hand side of engine contains fuel system

Right-hand side of engine contains fuel system

Common rail and high-pressure fuel pump

Common rail and high-pressure fuel pump

John Deere 9230 4WD Tractors use a PowerTech™ Plus 9.0 L engine that uses a common rail to supply fuel pressure to the injectors.  The gear-driven, high-pressure fuel pump instantly responds to requirements for more or less fuel flow or pressure.
 
The common rail (see image above) contains extremely high-pressure fuel and is the channel flowing fuel to each injector.  The pressure is generated by the gear-driven piston pump (see image above).
 
Each injector is controlled individually via the engine control unit (ECU). The ECU can sense engine rpm and load changes 100 times per second and respond instantly to them. Load and speed sensing allows each cylinder fuel delivery rate to be adjusted independently at the individual injector.  With each injection cycle, the ECU can make the following adjustments on-the-go: 
  • Fuel pressure in the common rail
  • Start of injection
  • Duration of injection
  • End of injection
 
Cold-weather and high-altitude compensation are also precisely controlled for good starts regardless of weather and proper power levels at high elevations.
The injection system also provides a way to have the engine run with a decreased noise level via a process called pilot injection. With the precise fuel injection capabilities, there can be a small amount of fuel injected early in the combustion process.  This helps lessen the combustion knock commonly heard from diesel engines. While the combustion noise reduction is most obvious at lower rpm, pilot injection continues to function at any engine speed.
 
Integration of this state-of-the-art fuel injection technology into the John Deere 9.0 L engine provides the necessary means to achieve improvements in operating performance, fuel economy, and exhaust emissions.
Electronic unit injection fuel system (13.5 L)
 
Electronic unit injector

Electronic unit injector

Electronic unit injection systems on the 13.5 L engines are used in the 9330 - 9630 4WD Tractors and 9430T - 9630T Track Tractors and provide the following benefits:
  • Variable timing control for improved emissions
  • Better control at start of fuel injection for improved starting
  • Elimination of nozzle service
  • The single fuel rail is a drilled passage in the head, eliminating the need for external lines for reduced service
  • Injection pressure has been increased for Tier 3 emission regulations
 
Full-authority electronic ECU on the 13.5 L engine offers the following benefits:
  • Programmable fuel delivery with electronic controls provides optimum performance settings to improve field performance.
  • Constant power range (range of engine rpm where engine power remains equal to or higher than at rated engine speed) covers 500 rpm.
  • Ten percent power bulge (37 to 52 additional horsepower depending on model) is available within the constant power range.
  • It eliminates need for periodic adjustment of engine idle speeds.
  • Self-diagnostic capability through CommandCenter™ display minimizes downtime.
  • Fast injection rates (13.5 L) improve low-end torque, reduce smoke, and minimize fuel consumption.
  • It provides for ignition key shut-off.
Four-valve cylinder head
 
Four valves on single cylinder - 9.0 L engine

Four valves on single cylinder - 9.0 L engine

The four-valve cylinder head provides excellent airflow resulting in greater low-speed torque and better transient response.
 
All 9.0 L and 13.5 L engines use a four-valve-per-cylinder design that allows a higher horsepower output than traditional two-valve designs with similar displacement. The two intake and two exhaust valves improve the airflow (pumping losses) both into and out of the engine.
 
Four valves per cylinder provide greater airflow with less restriction both in and out of the combustion chamber, greatly improving economy and lowering exhaust emission levels.  
 
The cylinder head is made of a one-piece, heavy-duty special alloy gray iron casting.   
Other four-valve head benefits are as follows.
  • The four-valve design positions the injector in the center of the piston and combustion chamber for even piston loads and mixing of fuel
  • Maintains cooler head temperatures through high rate of airflow
  • Raises air-fuel ratio while reducing internal operating temperatures for improved reliability and fuel efficiency
  • Valves and replaceable valve seat inserts are designed to minimize flow restriction.
  • Center-mounted injector is used to get clean, efficient combustion for low fuel usage and reduced emissions.
Self-priming pump
 
9.0 L engine shown

9.0 L engine shown

The low-pressure fuel system has an auto-prime feature.  Eliminates hand priming and filter pre-filling.  When you turn the key, the pump is turned on and automatically primes the fuel system.  The system will primes in less than two minutes at a filter change.
 
Last Updated : 25-Jul-2013