In a separate thread I posted about replacing the pickup tube as I was having fuel delivery issues. Well I thought I had it solved but it still is not working correctly. All the lines are new and leak free, have tried 2 rebuilt stock pumps and now I am on a NOS Carter civilian pump. The fuel filter is staying full for about the first 8-10 miles then it slowly empties out so the truck will barely run, you can see just a light spray of fuel going into the filter. So I removed the filter and installed a in line fuel pressure gauge, from a cold start it's showing a steady 5psi. After about 6 miles I checked and it dropped to 4.5psi, after about 8 miles down to 3.5 psi and arriving back home about 12 miles it was jut below 3psi. I let it cool off for a few hours, re started and it shows 5psi, just don't understand what is causing this, hopefully some experienced folks can provide some clues.
Thanks