Metal tip sensor? Did you buy the kit from Nissan or did you buy aftermarket sensors? There is a replacement sensor only from Nissan that is metal/metal tipped to correct the no start issue if you have no spark. You also need to verify fuel pressure. It can be either the sensors or the fuel pump. No gas or no spark as either will prevent the engine from running.
reply to Doctor Olds BTW The main relay (or fuel injection relay) fires up the fuel pump, the ecm, the ignition, and quite a few other things such as the entire electrical system (save for the starter and alternator).