There is a crank fuel table in the tune that (while in cranking mode) fires the injectors for a preset pulsewidth. Making your injectors 3 times larger than stock pretty much puts in 3 times as much fuel as stock. That would do it.
Also, changing airflow meter calibrations will have an effect on the overall fuel injected for sure, but it has no effect on injector characteristics. There's more to injector specs than just their static flow rate. Injector delay time, battery voltage compensation, breakpoint, and other things must be reprogrammed or the car will never idle right.
The larger the injector over stock size, the worse that problem will be. You should also know that as you reduce the airflow reading that the meter puts out, you also reduce the load the computer calculates. That increases spark timing, which could be dangerous or at least not ideal. You need a real tune.