Help! This sounds like this is my problem with a 1980 450sl.
I replaced a fuel pump check valve, a fuel accumulator and fuel filter in the hope it would cure a long cranking issue when hot.. Now when the engine runs, it is very lumpy and hunts while belching smoke, the engine runs fine when on the highway, although the fuel consumption is a dismal 10 MPG. It seems that I can not lean it out any by using the HEX air screw at the CIS. Any ideas?