Fuel Pressure Regulator: Description and Operation

Fuel Pressure Regulator And Pulsation Dampner Cross-Section:

PURPOSE
It keeps the fuel pressure applied to the injector 2.55 kg/cm2 (255 kPa, 36.2 psi) higher than that in the intake manifold at all times.

LOCATION
On the fuel injector rail.


OPERATION AND CONSTRUCTION
The fuel pressure regulator is diaphragm-operated relief valve consisting of diaphragm, spring and valve.

The pressure applied to the chamber "A" of fuel pressure regulator is intake manifold pressure and that to the chamber "B" is fuel pressure. When the fuel pressure rises more than 2.55 kg/ cm2 (255 kPa, 36.2 psi) higher than the intake manifold pressure, the fuel pushes the valve in the regulator open and excess fuel returns to the fuel tank via the return line.