Just purchased a 99 Chevy Silverado LT and every time we start it up we get continuous popping noises rough idle sounds like a misfire but everything's been checked new plugs new wires new coil packs and also not getting any thing from the fuel pump the relay has to be jumped at the fuse box in order for the injectors to come on to start it any help would work

 

start with the basics first. figure out why the fuel pump relay is not turning on. if its not getting the proper signal then something else might not also causing other issues.

cant really help you with schematics or anything right now but since its a 99 you should be able to find them online easy. find out where the fuel pump relay gets its signal from and back trace that. i would think its from the ECM but ill be assuming, find the wire for it at the egm and see if its getting signal. if not find out what tells the ECM to send the signal. should be on with KOEO (key on engine off) just to prime the system and then stay running once the engine starts.