Hi

This is my first post, I appreciate any help you can give me.
I have a 2003 CLK 320 that has an intermittent acceleration problem. Sometimes, while accelerating from a stop, the car does not respond. No rpm increase, no throttle opening sound, nothing. The foot goes down, but the engine continues to idle. Needless to say, this is a problem in traffic. The car has 46K miles and replacing the fuel filter did not help. Where do I start?

Thanks,