Coil Over Plug - Question on Black Wire

[n2motorsports]

I just finished the COP conversion and shortened the wires as recommended.  Now the car will not turn over.  I suspect the black wire, since it has a sheath over it and i wasn't sure what to do with it.  See pic below:

 

Initially, i just soldered that sheath into the connects 2,3,4 since i had shortened them, then the car wouldn't turn over.  So I cut the sheath part off and the car still won't turn.  I was extra careful to not cross any of the wires so i still suspect something is up with that black wire.  Does anyone know what i need to do with that sheath part?  I read elsewhere it acts as a ground, but i've got no idea what that means.  I suspect like most things, you would want a ground?

[keflaman]

http://www.e30tuner.com/bmw/articles_condis1.php

I think the outer wiring is shielding and not a ground. If you look at the pictures in the link, the author uses the black wire as an example in his write-up. (Refer to paragraph 9 under "Procedure").

I'll be starting my COP conversion soon, so I'm interested in finding an answer to your question as well.

[n2motorsports]

Update:

I removed the shielding and taped it up, and the car still had trouble turning over.  I just let it crank over and over and it finally caught.  I really doubt the sheilding was the problem but rather the car sat for over a month.