95 7.3 trouble cranking,running and no power

Dunno how else to title it.....was running great with no issues other then hard to start when motor was called down.....has 2 tanks so I filled back tank up and put 20 in front.....drove home and while idling in driveway I flipped tanks and made sure it was all working...seemed so.....I flipped back over.to back tank and cut it off.....little bit later I went to start it and it didn't wanna start...took a while and several shots a ether but finally fired up....ws idling fine...I tried to leave but it acting like it's out of fuel....want rev up and smoking badly...smell of fuel will make you cry....no strainer in tanks...dunno why....I took off selector.valve and blew.back through and made sure it wasn't stuck in middle....changed oil and fuel filters....dunno what else to do...don't have fuel pressure gauge