BMW Repair: BMW 2001 ci, mass air flow meter, mass air flow

Question
I have a 2001 325 ci. Started Nov. 2006 when out of town -car would die when trying to start. Car died at idle - had to get back home and stopped car for about 15 minutes and was able to start up again without a problem. Took to local BMW dealership where no problem was discovered via computer check of fault codes. Service writer started possible early start to problem of a cam sensor. Didn't happen for a few more weeks, then out of the blue happened again. Took to same BMW dealership where another service writer suggested ignition to be replaced (which I did) and also replaced the air boot as there was a crack.
Car ran fine for nearly one month when out of the blue again same problem with dying at start/idle. Could this be a cam sensor - intake or exhaust? Any suggestions would be appreciated. Robert - RobertNesman@yahoo.com  

Answer
Robert, cam sensors cause the car not to start or run rough then die at idle so this could be the cause. The faulty cam sensors (intake and exhaust) will have a tappered nose (stepped) the updated/improved style will have a square nose with no step. Usually the cam sensors will store a fault code. A sticking idle valve or an intermittently fault mass air flow meter will cause the same thing. I would try tapping on the idle valve with a long extention next time this happens.
-Evan
-Evan