Engine Still Won't Start?

96 Silverado 5.7L I bought the truck and was told it needed a Fuel Pump, I replaced the fuel pump and it' still wouldn't run, I also replaced the fuel filter, and checked the lines. Now I'm not 100% sure about the Spark but, when you spray Starting fluid into the Throttle body it will start for a few seconds, but for some reason there is no fuel getting into the engine. I also pushed the pin on the fuel rail the fuel is going to the motor, just something isn't working right, it cranks just fine and for the few seconds it does run it runs great. Also it does have the "Spider Injector's" If that has anything to do with it. Really appreciate all the Help I can get. Thank you