Need Some Help With A 380sl Problem

[Philoprof]

Came home from a 35 mile hwy trip in my high-mileage, 81 380sl last night. Pulled into the garage, turned the defroster off , and the car started misfiring and shaking, as the instrument cluster light dimmed and brightened. In addition, the garage filled up with exhaust fumes.

My first thought was the alternator. But the battery light didn't come on, I didn't notice the headlights dimming, and I restarted the car, after I had turned it off, In addition, it started it again the next morning, and ran perfectly, except for its usual, slightly, rough idle.

The following parts were all replaced, at one time or another:

Recently: Wires, distributor cap, rotor, coil, OVP relay, Idle Control Mod., plugs

Several years ago: Fuel pump, fuel pump relay, fuel filter, accumulator, head gaskets, chain, guides, valve guides, stem seals, etc.

Checked; Ballast resistors meet specs; Idle control valve meets specs and works fine

I suppose that one or more of the above things could have gone bad. And the only other things I can think of, which haven't yet been changed, are the ICU, fuel distributor, pressure regulator, thermo-time switch, and frequency valve --

The car is running perfectly again. But I suspect the problem will appear again, and I don't want to get stranded when it does So, I'm wondering if anyone could tell me what to look for now or when it does happen again.

Thanks very much in advance for any advice anyone can give me on how to deal with the problem.

Bill