96 miata won't start
 

I have a 96 miata m edition. I've been having this problem since a year ago. It has the engine light with the code of a bad crankshaft position sensor. Its being replace 5 times already and keeps doing the same thing. The car will run fine for a couple of weeks and then the light will come on and the car will just die. The car turns back on for few seconds and turns off again. I've send the car with lots of mechanics and nobody seems to know what exactly its wrong with it. I need help im about to sell the car but if i get it fix i would keep it. I appreciate any help. Thank you.