I have a 1993 Silverado and I am having a stalling problem. It has happened while driving and while I get in it and try to start it. If I put the pedal to the floor, it will start up but runs like crap and starts to come into it and pours out black smoke. It only happenes every once in a while. So far, I have replaced the distributor (complete AC Delco distributor), coil, plugs, and wires. The fuel pump was replaced roughly 5 years ago. The truck is a 5.7L and has 188,000 miles on it. I am starting to think it is a intermittent fuel pump problem that is getting weak because I have pulled the air cleaner assembly off while it would start and i saw fuel spraying into the throttle body and I have check to see if there was spark and there was. Any body else ever have this problem and if so HELP ME OUT!

Aaron C.