> -----Original Message-----
> From: Brian
>
> I guess I don't understand how cycling the key will produce more "volume"
> if
> the pressure doesn't change. The fuel pressure made by the pump is what
> pushes the fuel through the system. If the pump turns on pressurizes the
> rails, and then kicks off, cycling the key isn't going to do much more.
> It doesn't pump more volume as it's a closed system. It either has
> pressure or it doesn't, if it builds the required pressure than it will
> supply the required fuel.
It seems you are presuming the pump will pressurize the rails with one key
on cycle. If much, or all, of the fuel has returned to the tank while the
truck has been idle, that brief cycle of the pump may not push enough fuel
through the line to reach the rails. If the engine is not running the ASD
relay will shut off the pump after a couple of seconds.
A second or third cycle may be necessary to move fuel that distance. The
pump doesn't provide "pressure". It moves a certain volume of fuel with
each stroke and the pressure builds when the fuel can move no farther. At
that point a regulator bleeds off excess to maintain the desired pressure.
> And the fuel system on your '92 is a little different than
> his 2002. So that's like comparing apples to oranges.
>
> brian cropp
It's different only in that my '92 has a return line and rail mounted
regulator while the '02 has a pump mounted regulator that bleeds off excess
fuel before it enters the line. Same principle, different (cheaper)
approach.
Ray
http://www.dragtruk.com/ENTRIES/20KM1FD2KWBP.html
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