Driving the mighty 300SDLon a surface street at low speed, I floored the accelerator and something seemed to break. The pedal went almost to the firewall and now has only the smallest bit of travel. I can only get about 2000-2500 rpm out of the engine now. I looked at the linkage, but saw no obviously broken parts. The little plastic linkages all seemed to be OK. If I grab the linkage where it is attached near the cruise control device I can make the throttle move in what seems like a normal amount of travel, and can rev the engine much higher than 2000 rpm.

The cable from the accelerator pedal attaches to a black plastic lever, which moves about 90 degrees with out resistance and without affecting the throttle linkage. Is this normal? Any ideas about what broke?

Thanks!