You must have the car checked for stored fault codes. There are many things that can initiate this failure. The most common seems to be the Electronic Throttle Actuators. In my case, the car was throwing all sorts of codes related to the ETA's. Turned out to be the infamous disintegrating wire insulation. Read all about it here...
http://v12uberalles.com/throttle_actuator_rewire.htm
http://v12uberalles.com/MAF_rewire.htm
Another excellent resource...
http://pages.prodigy.net/jforgione/MB_asr.html