Reference Sensor question

[lerrysan]

I just replaced the crankshaft on my 92 300E with a m103. When the old crankshaft broke, it also broke the reference sensor. Today I started up the car and it started fairly fast for a engine that was just rebuit. It probably took 5 or 6 turns before the engine fired up. My question is "what does the reference sensor suposed to do". The engine starts up good and it runs perfect and its not connected because its broken.......should I get a new one or is that sensor really not necesary?