1994 Chevy Blazer No clue whats wrong!

I have a 94 Chevy Blazer, 170,000 miles. At Idle, its choppy sounding like its about to run out of gas. From 30mph or less, I have to have my foot on the gas pedal or it dies. At highway speeds it runs like your giving gas, letting go, giving gas, letting go. Real jerky! The "Service Engine Soon" light goes on and off. I gave it new plugs, wires, rotor and Distributer cap. At a complete stop I either need to lay on the gas pedal or it dies. I only have a key for a diagnostic test and it comes up with 32.I've called the local chevy dealership and they said it ws the EGR valve. I took it off, ran it through the parts cleaner, dried it out with the parts cleaner and reinstalled it. Same thing. At idle it rocks side to side bad and I can hear it sounds like its not getting enough air. Its pushing black smoke when I rev it up, and smells like gas pretty bad. I'm wondering if this could just be bad gasonline, or possible the fuel pressure switch or sensor. Or maybe the cam positioning sensor? Any ideas?