i'm not talking water necessarily, sometimes a small crack in the distributor cap can allow moisture to get into the cap and cause that issue

only reason i mentioned that was because you said that it rained and the acceleration issue, and that reminded me of what my problem was, or moisture in your spark plug hole.

i had both issues at once on different occasions and the problem was solved both times.

just go check it, it only takes a minute to check the distributor cap for moisture