Do fuel lines lose pressure when fuel pump not on?

[vancouverbc]

My pressure drops from 44psi to about 20 psi when fuel pump not on. This takes about a minute. Just wondering where this pressure is going. I pinched off the line just after the fuel filter and after the pressure regulator on return line.

[Fifth ace]

44psi is alot of pressure, it probably went trough the vice grip or wathever you used to pinch the lines.

[skylndrftr]

pressure can actually quite easily leak back through the pump. This is why your fuel pmp will turn on immediately prior to you starting the car, it needs to pressurize the system.

[Q45tech]

Quality oem pumps have an antidrain back valve and the fuel pressure regulator blocks the other end......................still it should stablize at 20 psi for a few days.

Cumlative leaks a drop here and there eventually drop psi how many days weeks is a mark of integrity.

[yokota180sx]

okon MOST stock systems, over a 12 hour period it will bleed the pressure off normally.

If you get a Good FPR, liek Sard, or Aeromotive, it wont.Its nothing ot be worried about