Spark plug wires, replacing connectors.

BMW sells plug wire components individually, so it is possible to make your own wires, or repair an otherwise good wire if one end is damaged.
To assemble these wires, special tools are required. BMW special tools are best suited to the job, but the job can be done with regularly available tools and a little improvisation.

Cut the bad end off the wire to be repaired.

Remove 6mm of insulation from the wire end.  Core is 1.5mm thick.

Install the connector on the wire end with the core protruding through the center hole and crimp the connector with BMW special tool 12 1 091 or equivalent.

Lubricate BMW special tool 12 1 092 and slide wire into boot until the wire connector snaps onto the back of the boot connector.

Test lead with an Ohm meter, paying attention to Ohmic values on each boot, usually 1 K Ohm per end.

BMW special tools are available as a set, numbered 12 1 090

E30 M3 Repair Manual V2.7.  Copyright ©1999-2001 Koala Motorsport & Brett Anderson