Pretty close,

    It actually regulates engine fuel mixture working along with injector
dwell. The fuel pressure regulator governs the amount of fuel "returned to
the tank". High vacuum, (engine idle) engine is leaned by more fuel return.
Low vacuum, (high RPM's) less return.
    This is really a simplified explanation, but you get the idea. This in
conjunction with the ECM and the catalytic converter makes all that clean
air we breath.

Howard

>Subject: Re: vacuum and the fuel pressure regulator?

> It correlates manifold vacuum to fuel pressure. High vacuum (idle), low
> pressure; low vacuum (open throttle) high pressure.