Stop For Lunch, Comeback To Crank But No Start

[2500HDR]

Ok guys, tell me what you think.

 

First time I've ever had any issues with my '06 2500HD Duramax LBZ/Allison with 74,000 miles all stock. Traveling last Saturday pulling my 5th wheel from Southern Oregon down Interstate 5 back to the Sacramento area after camping for a week. Stopped in Weed, CA for a quick bite after running through the ups and downs in the area, it was 2:30ish in the afternoon and in the high 80's, half a tank of fuel. Left the truck for about 30 minutes, came back, got in, cranked and it fired briefly and stopped. I cranked again but got no start. Over the next 3 hours I tried to restart with extended cranks a few more times. During that time I looked for things out of place and such, checked and had fuel at the bleed screw of the fuel pump housing and finally started pulling fuses for any circuit I though might have something to do with fuel pumps or ignition. It was after the fuse pulling and replacing that the truck started, but I think that was just coincidence. With the truck running I filled up and pulled the rest of the way home with no issues. Check engine light never came on during the extended crank periods and the truck runs fine today. So what are some thoughts? Vapor lock? Intermittent fuel pump?? Fluke???

 

Extra info after the fact. I changed the fuel filter 3 weeks before leaving on the trip with the napa gold plastic fuel filter. Maybe I have a torn o-ring.

 

Oregon uses a blended bio-diesel of 5% or 20% ratios. I purchased the B5 5% product for the week I was there. Is bio-diesel more volatile and prone to vaporization?