My c230 kompressor 1999, first it wouldn't start, the engine wouldn't turn over, towed it to a mobile station, crank sensor was replaced ($400), and mechanic wanted to change the gas pump and filter to make it run ($700), i decided to tow the car back to my house. kept in the garage for a week, and then started car, the car started, however, this morning while driving to work, the car lost power and topped, i managed to get it started again, but got scared. what do you think is the problem? help