should the fuel system always retain pressure?
 

having problems and trouble shooting

battery was removed from truck to get new one, decided to remove cap on fuel line and push in the valve and very very very little fuel came out. should the system still retain pressure with battery out and truck sitting without driving for 2 days?

hasnt been starting lately and just cranking away so I feel its either the fuel pump or CPS.

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.

Thats the thing that is stopping me from checking is the battery is utterly dead and therefore I have no power to re-pressure the lines to test. Im glad it is normal for the line to lose pressure because it literally had none. thanks bob