Truck keeps dying while driving

I have a problem with my 1995 12 valve. Without warning the truck will shut off while driving. Doesn’t happen for a few days then all of a sudden will happen. Sometimes happens on the highway, but also on two lane roads. On the highway it’s done it several times at 70 mph, once around 75, once at 60. On a back road I was going about 50 mph and it also did it. Weather doesn’t seem to matter. Did it in rainy 40* weather, and also today about 62* and bright sunshine.

The truck just dies and you coast to the shoulder. Can then restart and continue driving. Sometimes with no further trouble, other times within 10 minutes it happens again. One time I stopped for fuel after it happened and it sounded like the fuel filler cap was under vacuum when I opened it up – made a hiss or whoosh sound. But this doesn't happen all the time - just once that I noticed.

The problem definitely seems fuel related, but not sure what to check next. I’ve already replaced the fuel filter. Years ago I replaced the rubber fuel lines with the Foster(?) kit but it’s been 8 years probably. Anybody run across this or have any suggestions? Also any chance it could be computer related? I don’t seem to have any electrical issues and the truck has new batteries. Any help is greatly appreciated.