i had this issue before..similar to say the least
i was WOT my car and suddenly engine stall. long story short: it was ballast resistor failure. I dont know how ,as its just a resistor.
engine can start and running during cold start. since u change injector, probably can take a look.
took out one of the cylinder plug to see if theres anything wrong with ignition/coil, spark is there.
monitoring the afr gauge for any fault in fuel system, check out everything ok.
starter crank strong, i keep on crank + gas till battery kaput.
me and mechanic called two different tuner, both mention injector resistor ballast faulty. According to them, those ballast commonly fail during dyno tune. Ive send the car for dyno twice before, and fail while im on the road. Since then, i have spare ballast standby.