My '95 with the 3.0 V6 was hard to start and would start and begin to idle, but after a few seconds it would stumble and stall - right about the time that it would normally idle higher to warm up. If I hit the gas it will stall quickly. This was intermittent, and when it started OK then it would run fine under all loads and whether warm or cold, but the problem quickly got to the point where I was rarely able to start the truck.

I checked fuel pressure and had good pressure with the pump jumpered on, but it wasn't holding the pressure after the pump was turned off. So, I replaced the pump (the problem was actually a crumbling fuel line connected to the pump in the tank). I also replaced the fuel filter.

Now I have good pressure with the pump jumpered on, and it holds pressure fine after being shut off. The truck starts immediately but still stalls after a few seconds. I have checked for vacuum leaks and didn't find anything. I haven't been able to get the truck running again, so I'm having difficulty troubleshooting.

Anybody have any ideas what to do next?

Does it matter if the fuel pump is jumpered and you start it?

Good idea - I just went out and tried it, and yes the engine idled fine with the jumper in place. After about 30 seconds, I pulled the jumper and it stalled.

I'll have to look up the schematic, but this probably means that a relay is worn out?

Check the air flow meter, it is what keeps the FP running after you start:
- http://www.4crawler.com/4x4/CheapTricks/AFM/index.shtml