Engine won't turn over.

[E30Rookie37]

establish that you first have fuel pressure.

then do the above stated. i found that that crank and reference sensors on the eta are shit, some times... (not saying thats what you have going on, but it's possible)

Personally i would do this after determining that i have fuel pressure:
The bently describes a pin out of all the motronic 1.0 inputs (page 6-48 in my book), except the crank and reference sensors, which should be able to test at the connecting points on top of the valve cover (i think thats where they are on the '86)

i would check all of the inputs from the main harness and see what/if something comes up out of spec.

Edit: lets be clear briefly, because you never actually established; you do have an eta, right?

A 1986 325e indeed.