1992 Toyota 4Runner 92 Toyota 4Runner wont start

My 4runner was sitting for about 3 months, and when I went to start it, the battery was dead. I jumped it and got it started, but while I was letting it idle to charge the battery it ran out of gas after about 5 minutes (at least that's the most likely reason it died). I added about 2 gallons of gas, and had to jump start it again. My girlfriend attached the cables (perhaps in the wrong order), and there was a big spark and the 4 runner stopped registering any power at all. I checked the fuses, and the fuse marked 80amp ALT was blown, along with 2 15 amp fuses. I replaced those 3 fuses, charged the battery, and tried again. It cranks fast and strong, but wont start. What do I check next?