Can a high pressure fuel pump get "weak"?

[rusty ol ranger]

I always thought they worked or they didnt...

But today i had rusty parked on the hill by my shed overnight (engine pointed uphill from tank) and it seemed to take more starter revolutions to start then normal when im parked level.

Fine once it started. Just am curious.

 

[ericbphoto]

Maybe the check valve is failing or had something stuck in it, allowing pressure to bleed back to the tank overnight. Maybe fuel pressure regulator starting to fail? Maybe an injector leaking by?

if the pump is getting weak or starting to fail, I would expect it to die pretty fast.

 

[rusty ol ranger]

Maybe the check valve is failing or had something stuck in it, allowing pressure to bleed back to the tank overnight. Maybe fuel pressure regulator starting to fail? Maybe an injector leaking by?

if the pump is getting weak or starting to fail, I would expect it to die pretty fast.

Thats what i figured on the pump. The FPR and injectors are only a few years old.

I had between 3/4 and a full tank, So that wasnt it