I had a problem that sounds the same. When I used kickdown from a standing start, the car would take off rapidly and noisly but at least would go. I had the injectors, plugs and plug leads changed but the problem resurfaced shortly after.
I looked into the block diagram of how the electronic components should work and that indicated a mass airflow sensor (the car doesn't know how much air the car is using and so doesn't give it enough gas, kickdown tells the car that it has an emergency and to ignore a few sensors). I paid 150 Euro for a second hand sensor and after a five minute drive to let the car adjust to the new sensor, the problem was gone.


I had taken the car to MB and other very specialist lunatic engine experts (hence the list of replaced parts), no one found the problem. The kickdown test was necessary to prove it though