My recently-acquired 230SL has a later, 280SE engine. From the beginning, I've experienced noticeable pinging under any reasonably heavy engine load.
Today, I did some serious digging in the fact. manual, and discovered that the 062 distributor on my engine is for an emission-control engine. I dialed back the ignition advance to 30 BTDC w/ vacuum attached as specified. This alleviated the pinging, but now power really drops off with missing at 3,000 RPM or so.
The manual indicates that there is supposed to be a vacuum cut-out valve which defeats the vacuum retard above 2200 rpm or so. This valve is actuated by temperature and speed switches.. my engine does have two temp switches installed, neither is hooked up, and I don't believe there is a vacuum valve...
I'm in a quandry as to where to turn.. should I just give up and try to locate an earlier, non-emissions distributor? If so, which one, and will any mercedes 6 cylinder engine of these vintages yield a distributor which will fit in my engine?
230SL, 59 Jag MK IX, 65 Stingray Roadster, 89 Carrera Cabriolet