'87 735i Won't Start

[pryde]

Recently acquired this car for my daughter. Twice it wouldn't start when she was trying to drive it. Lights would come on with ignition, but engine would try to turn over. The first time it happened, 15 minutes later she tried again and it fired right up. The second time, I playe with it for 1/2 hour with no luck, but after we went and came back from dinner, it fired right up.

So, I took it to a local mechanic just to get some ideas. He pointed out negative battery terminal corrosion, post terminal not tight, etc. Rather than take a chance on the existing components, I bought new pos and neg terminals and cables, braided ground strap, etc.

I replaced the positive side first, then the negative side w/braided ground strap. I then had to cut and put new ends on the smaller cables that were terminated to the posts because the new terminal bolt was bigger than the previous. So now everything is wired back (I assume), but it now does all the time what it was doing previously (lights come on but not trying to turn over).

I've turned the key over, crossed the starter bolts with a screwdriver and heard it "whir" but nothing else happens.

So, based on feedback from neighbors I'm wondering about the following:

Distributor cap? (because shouldn't it turn over if I cross over the starter directly)

Computer reset? Someone mentioned an anti-theft device that locks out if disconnected from the battery for too long.

Bad ground somewhere that I am not seeing?

Something else entirely.

Why would the starter not "whir" if I am turning the key, but does when I cross over it? Is that an ignition switch problem?

Any advice would be appreciated, as I'm out of ideas.