1991 lumina 3.1 will crank but no start

this car is getting on my nerves i have a 1991 lumina with 3.1 v6 spent a thousand dollars in labor getting wiring harness repaired i am getting blinking light on my injectors when hooking test light to 12 volt source like im supposed to no continuity between battery power to injectors als what its supposed to do to terminal going to ecm i am getting spark my ignition module and coils are new injectors are showing 12.4-12.5 ohms across terminals all in spec new plugs new wires ecm replaced with gm replacement swaped chip from old computer like the books say injector harness has less than 4 ohms on all circuits as also in spec ecm light reading correctly code 12 no codes stored new crank sensor comression on all cylenders in spec will act like it wants to start but it will not run also have 42 psi fuel pressure and a confirmed full tank of gas what is wrong whu wont it start what am i missing......!!!!!!!!?????????????........help.... ....!!!!!!!!????????

Welcome to AF. Will it start spraying carb cleaner into the intake? What was wrong for 1k in harness repairs?