Brakes are great, no problem. This seems more like a problem setting idle at startup. It is random and happens whether the engine is hot or cold. To counteract I just give the accelerator a small stab and all is well. I'll start by changing the fuel filter, cleaning throttle body and checking the breather hoses. If that doesn't solve the problem I'll move on to other stuff. Is the fuel pump suggested before a possible culprit? Does Mercedes recommend its change? the car is a 99 vintage with 107k miles on the clock.