1991 camaro wont restart after warm up in close loop no injector pulse at cranking rpm has spark and fule pressure is normal ecm tps map iac all confirmed ok will start with fule added at air intake?

no injector pulse only after warm up sounds like an electronics problem. ive seen many computers that were faulty that had no codes . it could also be the prom chip. try replacing the ecm and injector fuses.