91 Pontiac Firebird Formula runs poorly and stalls?

Hi, I would like to get some people's opinion on my problem who may have had similar issues or know a lot about F bodies. Here is my problem: Car will start and run ok when cold. Revs (in park) fine up to around 3k rpms (I haven't tried higher when its cold) but when it starts to get warm i will rev it up to about 2k rpms and it will sputter around for a second and die. When i go to start after wards it usually goes, but its a very rough lengthy start. The warmer the engine, the worse it seems. NEW PARTS INSTALLED: plugs (all gapped correctly.. changed plugs twice - same problem), wires (all connected to correct spots I.A.W. haynes diagram), cap, rotor, module, coil... Fuel pump/strainer, fuel filter, Air filter, cleaned IAC, seafoam through TB, 28oz of lucas fuel sys cleaner in tank. I've removed the TPS and it moves fluidly with no sticking. I have NOT however ohmed out the injectors but they all click properly during engine run. I have solid state ign. timing. I'm sure that i am forgetting a few things, but any help would be greatly appreciated. Thank you