power loss in 85 corvette

was pretty sure it was in the fuel system ,checked converter it was ok..replaced the fuel pump and filter..replaced distributor and cap..(didnt replace coil)..plugs and wires are ok..its barely running like its fuel starved tho but guess it could be a sensor or relay.....anybody have an idea what could be the problem ..???:banghead: its back firing through the exhaust sometimes but not through the throttle body so dont really think its a timing problem.

Does it only miss at idol? I would double check the timing first if thats ok check fuel pressure at fuel rail if thats fine you could have a dirty injector. If it stays running long enough, play with each injector and see if you can narrow it down to the bad injector by unplugging the electical connector.