My wager, is the lift pump was having a hard time pushing through the clogged filter, and you were getting some occasional clogging in the fsv that made enough restriction not to allow fuel pressure. You wait some time or thump the valve and the blockage passes then it’s fine for awhile. Glad it was a simple fix
I've now clobbered a few tacos and several beer contemplating the evolution of the problem...I'll bet with you.
I have to make a run though Abilene and Wichita Falls, when I get back I'm thinking of the manual FSV conversion and the addition of the independent glass filters @ FSV. I really like that idea.
Also: Another 35 mi with no problems ... haven't had the cajones to try switching tanks yet...
Thank you again for your help'
Kizer