purchased this truck just recent ,not sure whats giong on , truck had a leaking injector line which i replaced and everything seemed fine but when it would get down slightly below 1/2 tank fuel it would start missing and wouldnt hardly run ,put some fuel in ( thinking fuel gauge may not be correct) and it would run just fine till back down to 1/2 . so i pulled the pump out of tank to check ,it had enough trash in the screen that i considered the pump may be starting to fail...picked up a new one ,put it in ,no juice to the pump now... plugged the old one back in to check,no fire to it now either. it was running fine this am but something has happened ?a friend suggested checking fuel relays ( not sure about their location)...any other suggestions would be greatly appreciated.