This does not sound at all like an accumulator problem. That only serves up high pressure fuel on cold start and is passive once running, unless the fuel pickup sucks air for a moment.

I recently changed plugs on my 560sl, and it ran fine for a few hours, then it started missing. Mine got so bad that the exhaust melted the hangers.

Even though I was very careful removing the plug wires and they showed no visible sign of problem, I discovered that 4 of the wires had failed. Two were delivering very little juice and two were total failures.

Either pull all the plugs and reconnect to wires or use the old ones and crank the engine while looking for spark at all the plugs, or check each wire from end to end with a multimeter.

I still believe that the platimun plugs that I installed on the old wires caused enough impedence change that it contributed to the failure.

The engine likes the big fat spark of the copper plugs much better.

Check the wires before looking for something more complex.

K.I.S.S. (hasn't failed me yet)