I have a 95 ford f150 5.0 long wheel base. Good truck. Drove good yesterday. Then last night I turned it off to get gas, tried to crank, it would almost crank a couple times then would just turn over.Its got fuel pressure and the coil is getting a spark. Put a little gas in the intake and it runs for a sec then stops. What is the problem. Purge line a plenty of fuel pressure. When cranking it Almost fully cranks up, but then drops to just turning over. What are your thoughts? Still sitting at a gas station, so quick answers would be Much appreciated.

 

From what you describe, "it's got spark and you have fuel pressure, but still had to add gas to the intake to get it to start" sounds like a fuel pump supply problem.
You should hear the fuel pump run for 2 seconds when you first turn the key on. Can you hear it run for that 2 seconds ? You might try rapping the fuel tank on the bottom while trying to get it to start. If it starts , don't shut it down until you get it either home or to a shop to check out the fuel pump and replace it if necessary.
If you have never done that job before I would consider having a shop replace it if necessary because if the tank is more than half full it will be heavy to lower and replacing that pump can become a real job without the proper equipment.