Ian has a point on where to start. The newer fuel pump relays do have different programing for the cold start valve.
I have adjusted many of these plates. You will not get it to sit even. You should have no more than 2mm of play when LIGHTLY pushing inward on the plate (stopping when you fill the resistance). If there is more than 2mm, you have to drive the pin to the left of the tower down with a punch...IF you go too far, you have to take it apart and start over. YOU MUST RESET FUEL MIXTURE (LAMBDA) AFTER DOING THIS.
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM