Chevrolet Repair: 1984 corvette 350 crossfire, vacuum leaks, accelleration

Question
real poor accelleration and dies out , dies out and backfires through throttle body,injectors  look and act good, when  squirt gas in throttle body  smooths out

Answer
You state that the engine smoothes out when squirting gas into the throttle body. This sounds like the engine is running lean on fuel.

Check for vacuum leaks.
Test fuel pressure.
Check for codes, scan data stream.
Make sure injectors have a good spray pattern.

That's all I can say off hand. It could be many things considering the age of the vehicle.