I have a problem on startup of my recently acquired 1975 450SEL , rough idle and surging for 3 or 4 minutes until the car warms up a little. Also surging on coast , again only for first 5 minutes or so from startup. Any ideas ?
Forgot to add , I am currently trying some Wynns Injector cleaner in the hope that that might help
I am running it on premium unleaded 98