1984 bmw 733i

First check whether is is producing a spark. You can buy a $5 tester for this.

Fuel pump relay would be my first suspect on one of these.

You dont have an ignition control module, your coil is controlled by the ecu.

First make sure you have 12V to the "+" of the coil and ground your meter on another part of the car. If you have 12V and you suspect the coil is bad, disconnect the wires from the "-" of the coil, turn power on, and ground the coil. It should throw a spark.

But I would suspect that you real problem is the crank sensor located on the engine flange by the starter. When you located the sensor you will also see another identical sensor right next to it. Swap the sensor locations as well as their connectors. If the sensor was bad then you will now have spark but your rpm guage will not work.

Blake