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2.8 Fuel System

Overview

The Cummins R2.8 includes a gear-driven mechanical fuel pump mounted on the back of the block (similar to the 24-valve 5.9L and 6.7L Cummins engines). No external electric lift pump is required.

Fuel System Components

Component Source Notes
Gear-driven fuel pump Included with R2.8 Mechanical, on back of block
Fuel filter/water separator Included with R2.8 Has manual priming hand pump
Fuel lines User-supplied Tank → filter → pump, return → tank

Fuel Flow Path

Fuel Tank
    ↓
Fuel pickup (in-tank)
    ↓
Fuel Filter/Water Separator (with priming pump)
    ↓
Gear-Driven Fuel Pump (back of block)
    ↓
High-Pressure Injection Pump (front of engine)
    ↓
Common Rail → Injectors
    ↓
Return line → Fuel Tank

Electrical Requirements

None - The gear-driven pump is mechanically driven by the engine. No fuel pump relay, ECM control, or safety shutoff circuit is required.

The factory Jeep LJ in-tank electric fuel pump is not used in this configuration.

Installation Summary

  1. Inlet: Route fuel line from tank pickup → fuel filter/separator inlet
  2. Filter to Pump: Route from filter outlet → gear-driven pump inlet (back of block)
  3. Return: Route from engine return fitting → tank return

Priming

Use the manual hand pump on the fuel filter/water separator to prime the system before initial startup or after filter changes.

Outstanding Items

None - fuel system is straightforward mechanical design with no electrical integration required.