Assuming the engine has good compression and all, gotta keep looking in two areas: fuel and ignition. I've seen either one hold an engine back. Have you tested your fuel presure and delivery rate? Kinda sounds like you are not getting enough fuel, but you actually have to measure and see if you are meeting specs. Almost sounds like a clogged strainer in the tank. They can be removed and cleaned or replaced fairly easy I think. Just be carefull with all fuel work. Gas is reaaly more dangerous than any of us realize. You changed the plug wires and that is a real good place to start. i have had plugs wires really stop me cold. How about the cap and coil? are they clean with no cracks or carbon tracks? I don't know what type of ignition that car has, but if it has points and condensor, change the condensor. Had a VW that drove me nuts until I swapped out the condensor. How mush vacumn does it run at idle?