you can read my thread (Subject: ML320 2000 model). Basically, I replaced the Crank Shaft angle sensor. Problem kept happening, troubleshooting at the Merc dealer started with Fuel pump and fuel pump relay, then lead to Electrical connections, the problem was finally diagnosed as a faulty Wiring HArness on the Engine Main management Unit. Just got my car back after spending a week at the dealers and I'm hoping problem is gone away. They seemed confident that it's gone.