I think I have your problem. This EXACT same problem just happened with my '94 4runner. My dad and I (I'm 16 by the way) could not figure out what was the problem at first, but once checking almost everything else, my dad figured out it is actually the starter. After removing it and cleaning it, it ran perfectly....for a couple weeks. So I had to go buy a new one ($160 or so from local auto parts store.) So try either cleaning the starter or buying a new one. I am almost sure that's your problem