fuel pressure regulator

A fuel pressure reguator maintains a certain pressure always. The fuel pressure regulator is usually located on the end of the fuel rail. The fuel rail covers the fuel injectors. The regulator has a fuel line running off it back to the fuel tank. The regulator has a little valve in it and pressure is controlled by the spring tension that keeps it closed. Simple adjustable regulators use a bolt that runs inside the regulator, to add tension on to the spring and valve. If the pressure is too high the fuel that escapes around the valve and returns to the gas tank. This always keeps the pressure constant. Adjustable fuel pressure regulators for turbo or supercharged vehicles are different. As the boost increases the demand for fuel becomes greater for the engine. To increase the fuel to the engine the fuel pressure is increased. The boost created by the compressor is fed to the back side of the valve. It is the same side as the spring. The increased pressure on the backside of the valve holds it shut more, increasing the pressure according to the boost. There is usually still an adjustment for the static or regular pressure.This allows the unboosted curve to be richened up.