No start -- Help Please!!

[jeffro22]

truck will not start.

batteries are charged, turns over, but wont start.

Almost sounds like last year when my crank position sensor failed.

Thoughts on what to check?

When I started the truck this morning (after sitting for 4 days) It took longer to crank. But it started a couple more times once warmed up without any issues.

The only thing that is weird, right before this happened, I took off a fuel line from my regulated return and replaced a fitting (it had been leaking diesel) SO I replace the fitting, and get the line hooked back up. Turn the key to pressurize the system a few times, Looking good at 60psi, but no start.

Cant think if anything I did when I took the regulated return off. Its mounted right near the alternator.

[jeffro22]

not pulling any codes on the scangauge.... Is there anything I can check with the scangauge (HP Oil?)