[PRegner]

I had the same problem when I put the TPI from a '91 Z-28 on my old 283 (outof an old '63 Vette). I finally tracked the problem down to a vacuum leak in the runners going from the plenum to the intake manifold. When the engine was cold, there was a ton of un-measured air coming in, and the system was dumping loads of extra fuel. When the engine warmed-up, the metal runners would expand; sealing the air leaks, and it would run great...