My 87 ranger runs for about 6 miles and quits cranks fine will not start?

runs perfect till it hits about 6 miles and dies like you shut the key off will not restart for between 4 and 6 hours then starts and runs fine - new distributor,pickup, coil, map sensor, distributor control module, trans speed sensor, computer, computer and fuel relays,high pressure fuel pump & filter. Planned on restoring truck - has 350k and except for this issue runs really good.