My vote is the injector dead time.

Are those high or low Z injectors? If they are low Z, you may not be opening them with enough hold current, and they will not open all the way, so MS thinks it is putting in a lot of fuel when really not much is getting in there.

Also make sure if you are running a fuel pressure other than what the injectors were rated at that you convert the flow over. I think 43.5 is typically used for flow specifications, so if you are running something other than that as your base pressure, convert the flow over to what it will really be. (Calculators online).

Oh yea, and what are you using for idle air control? Mine would start but die in a few seconds until I got my IAC set properly (Stock Stepper Based IAC). You can block it off and crack the throttle blades more to rule that out.