I have been seeing this issue more and more with vp44 equipped trucks as of late. The problem seems to be the fuel itself that is the culprit. If you had a fuel drain back problem the engine would not start easily cold either. You would also have a long crank time and most likely run rough for a few seconds and possibly some smoke. I have been suggesting to my customers to add a pint or so of 2 cycle oil to a tank of fuel to help with this issue.