generally bmw use very sophisticated management for the class of car and time. like individual knock sensors for each cylinder etc, etc.

E30 is old boxy shape 3-series?

you know yourself that these 'shoddy conversions' are just that. for less than the cost of a fifth injector kit, and a bodge to the afm signal, you could buy a megasquirt programmable fuel ecu and do it properly.

have a search around for it - hint, type megasquirt as one word in a search engine - mega squirt gives entirely different results (that i'm sure you've already visited )