My 2001 C180 W203 dies down after 2-3 hour drives. It's as if there were no fuel or oxygen to feed the engine. Mechanics say it's dirty fuel or the gas pump, however, fixing it doesn't seem to help the case. It keeps happening. The car is usually used for short trips, but every year or so it is used to go farther and unpredictably turns off. Is it a common problem for this generation C180?