Ok, quick update.
I put a FASS on my truck, and got the new VP44, and have put about 150 miles on the new set-up. Aside from the small oil leak in the timing cover, everything seemed great. 14 PSI in the fuel going directly into the VP *12 PSI @ WOT*, and great economy and performance. After about the first 50 miles, I noticed a slight drop in the pressure, about 13 PSI under light load and WOT. After that, every time I drove the truck, the fuel pressure dropped another point or two and wouldn't come back up. I also noticed that the performance and mileage have started to drop as well. I was about 20 miles from home camping, so I simply didn't drive it anymore than I had to. When I came back to town today, I had 6 PSI, and it dropped down to about 4 PSI by the time I got off the highway and parked it at my mechanic's shop.
The FASS pump was making a little more noise than when we first started the truck, and I'm wondering if anyone had any ideas. I don't have any fuel leaks, and the only thing I can think of is there might be an in-tank fuel pump. When I installed the FASS, we did a simple test to see if we could draw fuel easily out of the tank, and it seemed to work fine. It took three tries to prime the system , but after that everything ran fine, so I was convinced I didn't have to worry.
Does anyone have any ideas? I don't really know much about FASS pumps yet, nor do I know enough about these engines to determine what's wrong. Any help would be great, because I'm supposed to be using this truck Thursday to get 5 ton of gravel for the driveway. The gravel pit is on our way to the airport, and we're leaving for Alaska that day. Anyway, I'm off subject, and looking for help, lol... .