Fuel Rail: Description and Operation

FUEL RAIL ASSEMBLIES




The left and right fuel rail assemblies attach to the cylinder heads. The fuel rail assemblies distribute pressurized fuel to the fuel injectors through the fuel lines.

The fuel rail assemblies consists of the following components:
- The fuel rail pressure sensor in the right fuel rail
- The fuel pressure relief valve in the left fuel rail

The fuel rail pressure sensor gives the engine control module (ECM) an indication of fuel pressure. The ECM uses this information to regulate fuel pressure, by commanding the fuel pressure regulator open or closed on the inlet of the fuel injection pump.

The fuel pressure relief valve opens only to prevent excessive pressure in the event of a malfunction. Fuel from the fuel pressure relief valve is returned to the fuel tank.