Need a bit more info.
Has the engine been serviced recently? If so, details please.
Did this happen right after:
- purchasing a tank of gas?
- you poured in a fuel additive?
- poured in the remaining gas from a gas can?
- you loaned the vehicle to someone else?
If this is something out of the blue go to your local autoparts house and purchase Bentley's "Bosch Fuel Injection & Engine Management" book. ISBN 0-8376-0300-5. It's a wonderful compliment to the Mercedes shop manuals.
Hang in there.
S, J.R. Brown
2000 G500 LWB Obsedian Black
2005 Toyota Tacoma Access Cab Off Road Sport
1993 Volvo 240 Sedan Anthracite
1980 450SEL Champange (owned it for 15 years. Great car)
1986 280GE LWB Anthracite (Sold it and kinda wish I hadn't)