First I noticed there was no fuel in the carb (brand new fuel pump) I cranked the engine but no fuel came out, so I went to the hose that attaches to the fuel pump. No fuel in the line leading to the fuel pump. I then went to the tank, new tank and fuel sending unit, I pulled off the hose at the tank and no gas was ever in the line. So what do I do now, is it my fuel pump, what exactly does the fuel sending unit do. Any suggestions?