Does not hold fuel pressure when off, common suspects?

[es.biggs]

My car has been having issues starting every once in a while and I put a gauge on it this morning. The pressure was fine when running and the pressure regulator is working fine. I smelled the vacuum hoses on the regulator and damper, no fuel smell.

All hoses under the hood are brand new, and I know they are not leaking. Injectors were replaced by Nissan 10,000 miles ago, before I bought the car. I replaced the insulators when I had my engine taken apart 700 miles ago.

Is the return line a prime suspect? Where exactly does it run?

Thanks, Ethan

[marty1mc]

The return line runs directly next to the fuel line. When you look at your engine the fuel flows from the fuel filter, through the hose to the damper, through the fuel rail, to the pressure regulator and then back to the tank.

[robomatic12]

There are check valves in the fuel pump that may not be holding pressure.

[BigTDogg (MA)]

Gas cap? I think emissions stations can test it to see if it's holding pressure.

[es.biggs]

Not in my state...It lets out a pretty hefty whoosh every time I take it off so I think it's good. Should it still be under pressure in the morning after it sits for a while?