Originally Posted by rangerrunner11
so does the fuel systm retain pressure for upward of a day maybe 2 and without the battery connected?
There is a check ball that should prevent fuel from moving from the fuel lines back into the tank after the pump turns off. It usually holds some rail pressure for anywhere from several minutes to several hours after shut down. Eventually the pressure in the lines and rails will drop to tank pressure which is near zero compared to running line pressure.
Anyway, the short answer is that it doesn't matter if the pressure drops off after a day. However, the fuel pressure should come right back up to max as soon as the ignition is turned on.