3408 HEUI fuel system

The electronic components in the HEUI fuel system are very similar to those used in other EUI systems. However, in the HEUI system, the injectors are not actuated by a camshaft.

A high pressure hydraulic pump, which draws oil from the pressure side of the lubrication pump, raises the pressure to a maximum of 22800 kPa (3300 psi). The pressure is controlled by the Electronic Control Module (ECM). The hydraulic flow is directed to hydraulic actuators in each injector.

The injectors are electronically signalled (as in the EUI system) to permit oil under high pressure to move a piston which then moves the fuel plunger.

3408e component diagram

This diagram identifies the external HEUI system components (shown on the engine harness side of this schematic). The components shown on the left side of the diagram are mounted on the engine, and those on the right are machine mounted. Notice that the turbo inlet pressure sensor is mounted on the machine.

Electrical Components

  •  ECM 40 Pin Connectors
  • Personality Module
  • Timing Calibration Connector and Installation Location
  • Hydraulic Pressure Sensor
  • Hydraulic Temperature Sensor
  • Secondary Speed Timing Sensor
  • Coolant Temperature Sensor
  • Atmospheric Pressure Sensor
  • Turbocharger Inlet Pressure Sensor
  • Turbocharger Outlet Pressure Sensor
  • Oil Pressure Sensor
  • Fuel Temperature Sensor
  • Coolant Flow Switch
  • Machine Interface Connector
  • Engine and Machine Ground bolts Data Link Connector
  • Throttle Position Sensor
  • Shutdown Switches

Mechanical Components

  •  Hydraulic Supply Pump Group
  • Pump Control Valve
  • Compensation Valve
  • Cold Start Reservoir Check Valves
  • Fluid Manifold
  • Water Separator/Primary Filter Secondary Filter
  • Transfer Pump
  • Pressure Regulator Valve Injector
  • Jumper Tube Injector Oil Adapter

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