Could be bad/cracked/nicked/rolled o-rings, cracked injector, cracked head, or a few other odd/rare things.
Do a bubble test on the fuel system.
Basically, pull the secondary fuel filter and leave the cap off. Then fill the fuel filter housing with fuel(you can key on for this or fill from a jug).
Then with the key out of the ignition, use the starter wire on the passenger side fender to jump the starter.
This will crank the engine but will not attempt to fire it.
Crank it over for 30-45 seconds. Watch for bubbles in the fuel filter housing.
If you have bubbles, then you have a leak to chase down. If there aren’t any bubbles, then allow the starter to cool down and repeat the test.
Repeat it several times-leaving time for the starter to cool in between.
If after several cycles, there are no bubbles, then come back here and we’ll give you another direction.
If there are bubbles, then the next step is to idiopathic which bank they are coming from.
To do that, you will isolate the fuel lines and repeat the test.