I have a 96 Chevy Blazer 4

I have a 96 Chevy Blazer 4.3 Vortec Spider Injection 4x4. Ive been The past 3 months trying to figure out this dreadfull random misfire code. I have done alot of research and have repaired about everything I can think of besides the spider injector cause it cost so much and I dont have the money anymore. But today I decided to pull the car into my garage and take it apart to look at the spider injector. When I put it back together and started it up it would idle real rough and when I put it into gear it would lose power and shut off. Not sure why it is doing that. Remind you before I pulled it into the garage it only had a misfire problem between 10-30 mph and would idle completely fine or even when I put it into gear. What would cause it to act the way it is now and what could also be my problem to resolve the random misfire? Also you can smell gas real strong and the auto part store said it was running rich and not putting out 50% air and 50% gas.