Check your injection nozzles to see if they are made of steel or brass. A standard magnet will determine the metal. If they are steel they will need to be replaced unconditionally. They were updated to brass when MB found out that steel rusts very quickly because of the moisture in most fuels. If your injection nozzles are brass they still could be faulty from everyday corossion. The only other possibility that comes to mind is a faulty fuel accumulator that is located near the fuel pumps.
Thanks for the kind words of encouragement.
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM