With batch fire and a divider of 1, all the injectors fire every engine event, 4 times per cycle. setting the divider to 2 will halve the injection events resulting in the injector firing only 2 times per cycle, but the injector squirts twice as much (required fuel value is doubled).
One thing i am unsure of is what the required fuel calculation is calculating a figure for. I think it is a figure for sequential injection where the injector fires once per cycle, if you then decide to run batch fire with a divider of two, i would think the required fuel value should be halved, or batch fire with a divider of 1 the required fuel value should be halved and then halved again. This however, depending on how you have sized your injectors will determine how big or small the pulse width is. If you sized your injector to be big enough to provide all the fuel in one squirt (sequencial), the same injector will be massively oversize when running batch fire with a divider of 1. If your calculated required fuel pulse width is already small, running batch fire with a divider of 1, the pulse width will be quarter of that, and idling will be problematic?
There is no reason not to run sequential injection, as long as you have wired the injectors to individual output channels on the ECU.
The required fuel value is the figure the algorythms use to determine the injector size, thus it can determine the size of the pulse width to provide the required fuel for the current operating condition.
This theory is a little unclear and i cannot find anything in the Wiki about it. Needles to say, i was untill recently running a divider of 1 on what would be concidered batch fire, i had to halve the calculated required fuel value. after some thought and a little experimentation, I now run a divider of 2 and i now use the calculated required fuel value, with the VE values the same, still achieving the same fueling
I hope i havent confused you too much, LOL
if i have, just ignore what i said, lol, im just brain dumping