Fuel Pressure Regulator: Description and Operation

Fuel Pressure Regulator:

DESCRIPTION
The fuel pressure regulator is a diaphragm operated relief valve having the fuel pump pressure on one side and the regulator spring pressure and the intake manifold vacuum on the other side.

OPERATION
The function of the fuel pressure regulator is to maintain approximately 350 kPa across the director spray plate under all of the operating conditions. The pressure regulator compensates for the engine load by increasing the fuel pressure as the engine intake manifold vacuum drops. The pressure regulator is mounted on the fuel rail.

With the engine running at idle, the system fuel pressure at the pressure test connection should be 317-407 kPa (46-59 psi). If the pressure regulator supplies a fuel pressure which is too low or too high, a driveability condition will result.