My 2002 Dakota 4.7 loses fuel pressure as soon as you cut it off. Goes from 50 to 0.
It's also very hard to start when the engine is warm. It just cranks or starts and barley runs for a few seconds then runs fine.

Starts right up when cold.

Since I'm losing fuel pressure how can I know if it's the check valve or a leaky injector? I run seafoam or Lucas injector cleaner every oil change.

 

Man, that's a good one. I would default to a check valve, though a hung injector would make it hard to start as dead rich.

 

LOL I know it's a good one...... but I would think that it would take more than one and be hung wide open to loose pressure that quick.

I think my best option is to disconnect the fuel rail and hook pressure gauge directly to the line coming from the pump. Guess that would rule out what one it is.