Fuel Rail: Description and Operation

Fuel Rail Assembly Flow Diagram:

Model R620 Fuel Rail Assembly:

PURPOSE
The fuel rail assembly delivers fuel of equal pressure to all 6 injectors and routes any excess fuel supply back to the fuel tank.

OPERATION
Fuel is delivered from the pump through the fuel feed line to the inlet side of the pressure regulator From there, it is directed to both fuel rails. Fuel in each rail flows through the feed section of the smaller passage into the main supply conduit, supplying fuel at the same pressure to each of the injectors.
Fuel in excess of injector needs flows into the return section of the smaller passage, and back through the pressure regulator assembly, which maintains correct system pressure. Fuel then flows from the regulator through the fuel return line back to the tank.

COMPONENTS
The Model R620 fuel rail assembly is made up of:
- The left hand rail, which delivers fuel to the even cylinders (2, 4, 6).
- The right hand rail,which delivers fuel to the odd cylinders (1, 3, 5).
- The fuel injectors.
- The pressure regulator assembly.

The rail assembly is mounted to the lower section of the intake manifold and distributes fuel to the cylinders through the individual injectors.