I Have A 97 C280 That Wont Stay Running. It Will Fire Up But Then Cut Right Off. Now If You Dump Fuel Thru The Throttle Body Tll Stay Running. Or If You Unhook The Vacuum Hose Off The Regulator And Put It In Fuel Itll Run. Now Ive Changed The Fuel Filter, Check The Pump And It Is Pumping And Im Stumped And Any Help Please. I Also Had The Ignition Tumbler Changed And Ordered A New Key From Mercedes. Then A Week Later It Started This