Your earlier posts made it sound like the truck had stopped running at all. I would t worry about the lines then. If it runs when the temp is up, but not when it's cold, it could be an issue with power delivery or grounding. Highly likely the FPDM is bad, not providing enough amperage to the pump when it's cold. Could also be the ACT sensor (built into the MAF or located in the air intake system).
If the engine has high miles, and you haven't personally changed the spark plugs, or have a record of it being done, it's probably a good idea to check and probably replace them. They are $8-15 each for that engine depending on where you buy them, and of course you'll need ten. I've seen the 3-valve plugs totally trashed in a stock '06 Mustang with just 65k on them, the gaps were over 0.120"! They start with a gap of around 0.050"! This particular plug design really needs to be changed every 25k on these engines.
For what it's worth, the bigger the gap, the more resistance the plug has to jumping the spark. Combine that with colder denser air also increasing the resistance to the spark in the cylinder, and you may have your culprit. If the computer has sensed that there are misfires and unburned fuel present it may have trimmed the fuel to te point that the cold mis is just too lean to fire.
Be VERY careful removing the plugs though. These plugs are notorious for breaking off the projected ground and porcelain in the head, and then you have to have the dealer or someone with the special tools remove the remnants. Gently back the plugs off 1/8-1/4 turn and spray a good penetrating oil with a solvent component to loosen up the carbon down near the threads, the let them sit for an hour or more, then gently work them out. And they are a goofy 9/16" plug, so you'll possibly want to buy the correct spark plug socket.
The Current Truck (Oct-2013 to Present):
1999 (Early) F-350 Lariat, CCLB, SRW, Black/Tan
7.3L Powerstroke, 4R100, 4x4, 3.73, 37x13.50-18s, '05 Axle Swap, 6" Fabtech lift, GTP38 "D66" turbo upgrade, SCT 4-position chip with custom tuning by me, Straight Piped 4" down pipe through 5" dual stacks, N-Fab full length triple steps, Pro-Tech cab guard and tool box, louvered 5th wheel gate, Hella 500 Fog and Driving lamps, much more to come...
The one I'll miss, (Mar-2009 to Jan-2014):
2000 Excursion XLT 4x4
6.8L V-10, 4R100, 4.30, 285/75-18, 271whp / 388wtq
The one I won't, (Jul-2005 to Sep-2012):
2005 F-350 XLT, CCLB, SRW, 4x4 FX4
6.0L PSD, ZF-6S650, 3.73, 35x12.5-18, 4.5" Lift