I have a 95 Z28 misses badly under load. I noticed this morning that when the car is cold there is little or no miss. within 5 minutes the miss is back. I am curious....Opti?.....( new wires, plugs, fuel filter, fuel injector flush...any ideas?????????? Car is in the shop today.

 

I'd bet you have an ignition wire(s) going bad.
My car acted exactly like this when the wires were going bad...fine cold and as soon as hot there was a hideous miss.
A new set of MSD wires solved the problem....might as well change the plugs and coil while you are at it.

 

I have already done plugs, wires, fuel injector flush, fuel filter.....but you are right when my wires got replaced the problem went away for a while

 

the stock/oem wires have a habit of burning up and going bad, i've put on 3 sets in just over 1 year! They're in a horrible location, surrounded by hot @$$ exhaust and emissions piping, running right underneath a serpantine belt, theres a toooooon of things that can go wrong with them, id still give them a check at night, see if you spot any fire works.

 

I put on new AC Delco wires, and now that you mention it this miss is exactly like the one that I had before. So it seems as though I could have gotten a s**tty set of wires right out of the box!