What is the problem? Bad starter? After that dudes post I read, he says that he hears it spin, but doesn't start. Do you hear kind of a clunk?
A good chance it is your starter. Replacing a starter on an e36 IS NOT FUN. I do not recommend doing it, I sure as hell won't do it myself again. You need the right tools, and even if you do have them like I did, it is ridiculous. I hope you have girly arms.
If it is this, you can get a refurbished one for... 200 bucks? then if you find a mechanic who is experienced with e36 starters, he could probably do it in 2 hours.
I installed a new one in my car... took me like 13 hours.... it was ridiculous... funny thing is, the one I bought was shitty and burned out already... haha.
Brought it to my BMW mechanic and he said that he doesn't want to do it, and told me to do it myself again. I got someone to charge me for an hour and a half, but it took them longer of course.