Fuel Pressure Regulator

Located on fuel injector rail, this diaphragm-operated valve adjusts fuel pressure according to engine manifold vacuum.

As engine manifold vacuum increases (closed throttle), fuel pressure regulator diaphragm opens valve, allowing pressure to bleed off through fuel return line, reducing fuel pressure.

As engine manifold vacuum decreases (open throttle), fuel pressure regulator diaphragm closes valve, preventing pressure from bleeding off through fuel return line, increasing fuel pressure.