I have a 450sl 1977 and have had similair problems. First, the subframe (on recall ifyou know about it!) developed crack, local garage found it, dealer did not advise!! Also did not correct when in for previous service! After a lot of pressure got partial reimbursement from mercedes.If subframe ok? check bushings, replace if needed. If new subframe, get new bushings installed by mercedes (at reduced cost). If original fuel pump at 70,000 miles, suggest replace pump and filter. I cost me over $1000 at cheater mercedes dealer to finally do this AFTER HIS LOUSY REPAIR). good luck, Abe G