96 Won't stay running.

Ok here is the problem, I have a 1996 f 150 4.9 300 cubic inch 6 cyl. When you start it it will idle fine right up until you try and give it gas. Somone told me TPS sensor so i replaced it and nothing....Then i started messing with the coil and while it was running if i would push down and towards the engine on the coil wire with a screw driver I could rev it up fine.....Now i do know that the truck did get hot once before i got it....The plugs when i pulled them out the metal part of the tip was white.

Sounds like a vacuum problem. Check the fuel pressure valve for leaks.