Thanks again for the picture. It helped me figure out my problem.
Time to publicly confess my dumb mistake.
I got this truck already disassembled and it had no vacuum diagram, so I had to sort out the vacuum hose routing the old fashioned way.
I also had to replace the fuel pump on the 2.3. The pump diaphragm spring was broken and the diaphragm also appeared to be leaking. Quite a pain to get to it, I should have replaced it on the bench when I was replacing the head.
So when I installed the new pump, for some reason, I connected a loose vacuum line to the vent drain fitting on the pump. Long story short, the pump worked OK while cranking the engine but not at all when the engine was running - vacuum applied to the back of the diaphragm kept it from pumping fuel.
After sleeping and thinking about it, I remembered hooking up this line. Went out this morning and removed the vacuum line and the new fuel pump now works fine. DOH!