Ok here's the story. My car's a 1987 rx7 turbo, new engine. One day it suddenly was running very rough and could barely produce power. I pulled over and noticed a sparkplug somehow fell out (that's my godly bad luck acting) so I thought the engine might be flooded but after driving it a block it only got worse. Then while it idled black smoke came out near the rear tires, and now it won't even start. I checked the fuel pump, it worked fine, spitting fuel when we tried starting it. I recently got some test results for my sparkplugs (which had fuel in them when I pulled them out) and they're all clean now but passed the tests beforehand perfectly. Anyone know what the problem could be?