Another "no start"

[Big Blue 28]

OK so about 3-4 months ago my 03 6.0 started losing oil pressure if it sat overnight. After 2-3 attempts to start it would fire up and run fine, starting would not be an issue if it did not sit for over 24 hours. Started it up today and it felt like it was idilng a little funny started driving and it seemed to be in "limp mode". Shut the truck off to let it "reset" and it would not fire up. Doesnt sound like the injectors are even trying, I'm guessing due to loss of oil pressure. I intend on repairing it myself but where do I start in terms of diagnosing problem? Thanks in advance for any help with this.

[southend]

Without a monitor of some sort, it may be hard to diagnose.......Write Up: Monitoring the 6.0L PSD.

Sent from my phone that somebody didn't help me get.