Why does my BMW crank several times before starting?

Usually it can be one of a couple things. the first and cheapest thing to do is to replace the fuel injector relay about $10 at azautohaus.com. if that doesnt improve your issue then i would move to the fuel pump. about $50 on eBay if u need to replace it. and lastly it could be your fuel pressure regulator. test your fuel system pressure before you buy the pump or regulator tho. buy a service manual for your car at autozone to learn how to test the fuel pressure on your car. it will also tell you how to replace the pump and regulator on the car if need be. also check the forums online at bimmerforums.com for additional help!