Hey Jason. I've just got home and read this thread. I'm concerned about this third injector, as MS II only supports two banks of injectors. I could be wrong though, anyone else wishing to pipe in, pipe in. Your MS II as tested though, is only set up for two banks (high impedance or low using PWM peak hold), which can be run as alternating or simultaneous. You will most probably run as alternating!
Why do you need three? Two 400cc will give ~ 125BHP @ flywheel with BSFC 0.55 and 90% Duty cycle, you might look to get slightly larger ones. Are these injectors low impedance or high? See
http://www.witchhunter.com/injectorcalc1.php for a injector calculator. Try to use an injector that is close to your max expected HP, don't go to big as you might run into idle problems as the opening time at idle will get smaller. Also if you get the 'dead time' specs, or as I did I calculated/measured them my self. Having the settings makes tuning the VE etc a lot easier.
If you were to upgrade the MS II to a MS III with a MSX board, you can control up to 8 high impedance injectors. I think you can get away with just the two. On my NA 1310 which is most probably putting out 60BHP @ the wheel, it's only got one 620cc injector.
Sorry if this is a little garbled, just come of a late shift, and getting ready to call it a night as have a 7am start.
Cheers,
Jim