How Do VW, Audi, and Other Fuel Pressure Regulators Work?
Whether we talk about VW, Audi (or any other car for that matter), a fuel pressure regulator serves the same purpose of maintaining constant fuel pressure to the fuel injectors. With raised pressure comes increased flow. When fuel pressure is dropped, flow is diminished. The objective of regulating fuel is to achieve the appropriate ratio of air vs. fuel. This has a direct effect on emissions as well as power and response. ALL fuel injected vehicles regulate fuel pressure by one means or another.
As already mentioned a VW fuel pressure regulator or an Audi fuel pressure regulator is important because it maintains a “differential fuel pressure” which is measured at the fuel rail. This pressure is preset and will generally increase linearly. (Some special FPRs increase pressure at a rising rate that exceeds 1:1.) Any amount of fuel that is not needed to maintain required power is sent back to the fuel tank via a fuel return line. Eventually, the pump will recirculate it in a continuous loop between the front and back of the car.
So as to determine needed fuel pressure, a vacuum hose is linked from the regulator to the intake manifold. Inside the FPR, a diaphragm and spring assembly responds to fluctuating manifold pressures. Under vacuum (which sucks fuel out of the rail), the FPR drops pump pressure. When under boost (which pushes back against the fuel injector’s flow), the FPR increases fuel pressure. In this operation, the rail pressure varies constantly, while the “differential pressure” is held constant. Thus, the net fuel flow rate is maintained under all engine loads.
Now, it should be evident why an FPR is so important and how important it is to get it replaced as soon as possible when it is not functioning properly. A malfunctioning FPR cannot maintain the set pressure and that will inevitably lead to reduced performance, lowered efficiency, and dulled response.
Now, it should be evident why an FPR is so important and how important it is to get it replaced as soon as possible when it is not functioning properly. A malfunctioning FPR cannot maintain the set pressure and that will inevitably lead to reduced performance, lowered efficiency, and dulled response.
Author’s Bio: The author is a blogger. This article is about how FPRs function and their value.
