BMW Repair: Non Start--Engines Cranks but doesnt kick over, camshaft sensor, crank sensor

Question
I have a 1993 325I, most recently Ive been having problems with starting my car. One day I was coming home from work and the car drove fine. When I got home I parked it, came back out about an half hour later to start it and it wont kick over. After a few more trys it did start and I didnt have a problem starting it for a couple of days. Then one day while I was driving it actually shut off. I pulled to the side of the road and then tried to restart it. It took a couple of tries but then it finally started. Eventually I got it home and now it wont start at all. It cranks but just wont kick over. I have asked a few people what it could be and one said it sounds like the camshaft sensor and another person stated it could be the crank sensor. Is this something I can replace my self or are any of these individuals correct. Please Help.

Answer
The crankshaft and cam sensers are known weak spots but without proper testing it would be a shoot in the dark.
If you are willing to go that route I would try the crank senser first as that will cause a complete no start.
 You can do it yourself if you have the proper size metric male 6point allen wrench. Sears carriies a set of them.
  The cam senser involes removing the vanos solinode and would be potentially tricky for a novice.
 Buy yourself a Bentley  or other manual for further details.