changed the fuel pump it still won't start

Why did you replace the fuel pump? Low pressure , or pump not coming on? IF pump was not coming on , was any circuit troubleshooting done to verify the cause? Voltage to pump? Relay (ASD relay) may have a sticker under the hood mentioning a safety shut-down. got gas?-the Truck , that is.......

Pull one of your o2 sensors, see if it starts then, if so, your catalytic converter (exaust area) is clogged up possibly.