Fuel Rail

Courtesy of JAGUAR LAND ROVER NORTH AMERICA, LLC

The fuel rail is located on the top of the engine and it is attached to the cylinder head with 4 bolts. The fuel rail also secures the 4 fuel injectors in position. An O-ring seal on each injector locates in a bore in the fuel rail. As the fuel rail is tightened to the cylinder head the fuel injectors are retained between the fuel rail and the cylinder head. The fuel injector clamp on each fuel injector provides appropriate force to hold the fuel injector in position.

The fuel rail incorporates a threaded boss for connection of the High Pressure (HP) fuel line.

The fuel rail comprises a harness, which provides the connection between the fuel injectors and the engine wiring. The harness is secured to the fuel rail with 3 clips.

Fuel Rail Pressure and Temperature Sensor 

The Fuel Rail Pressure and Temperature (FRPT) sensor is located at the top of the fuel rail. The FRPT sensor is screwed into a threaded port and sealed with a mating taper in the fuel rail. The sensor is connected directly to the Powertrain Control Module (PCM).

The FRPT sensor is a metal thin film technology type sensor. The FRPT sensor is connected with 4 wires to the PCM. The PCM supplies a 5V reference voltage to the sensor. The pressure measurement is based on the expansion of a thin steel diaphragm which is sensed by the PCM on a return signal wire which is proportional to the fuel pressure in the fuel rail.

The PCM compares the sensor signal voltage to stored memory values, to calculate the actual fuel pressure present in the fuel rail. The PCM then uses the fuel rail pressure information to control the operating position of the fuel metering valve.

The FRPT sensor contains a Negative Temperature Coefficient (NTC) sensor which allows the PCM to determine the fuel temperature.