I was on the brakes, setting up for a turn, so yes, foot off the gas. Not sure what the engine speed was but I doubt it was fully back down to idle speed.

I know you posted above that you replaced the distributor cap and rotor, but have you pulled them off to check their condition since this problem has been going on?

Additionally, is the OVP you installed used, or is it brand new? If it's a used one, I'd suggest replacing it with a new one. When they get flaky, they can be maddeningly difficult to troubleshoot.

If you're handy with a soldering iron, it may be well worth your time to take the cover off the MAS relay and look for broken solder joints on the pins of the circuit card and the pins of the relays.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

The OVP was new. I haven't checked the cap and rotor but I will. I'll probably also order a MAS relay too.