89 IROC with the 305 TBI 5spd new plugs, wires, replaced dist, dist cap & rotor, map sensor, temp sensor at front for ecm, cleaned tbi-new gaskets, checked egr seems fine, new O2 sensor, no codes except when I mess with something

the engine runs good (smooth) when first started until it begins to warm up, then it misses and starts to surge to the point it dies. Starts right up again. When warm it runs pretty good, doesn't die. Runs good driving city\hiway speeds.
Don't think it's lacking fuel because it pulls good under load without missing.
Injectors look to put out a good pattern
Sprayed carb cleaner around intake and carb base looking for leaks but no difference in idle. Pulled off the AIR system, (after problem started) no change but it's way easier to work on now. Might even be able to check compression now.