On Fri, 17 Dec 2004 wrote:

> Just curious - what is it that tells the fuel pump to quit pumping
> before the engine starts? The pressure regulator only holds the
> pressure at a certain level and returns the excess back to the tank,
> right? But that's with the pump running continuously. Something tells
> it to stop when the key is on but the engine's not running.

The initial "Bzhhhhht!" that you get from the pump when you turn on the
key is just a timed pump pulse of (nominally) 1 second. The purpose is to
pressurize the system for engine startup. It's not necessary to monitor
the pressure, because as you know, the pressure regulator makes sure
there's no overpressure.

DS