coils are wierd things....lots of intermittent problems.
They get hot and short out and still work, but not "like they should"
My 560SL had a hesitation that I thought was a fuel distributor/injector problem....turned out to be a coil. Mechanic said it was just out of specs.....not by much, but enough to not provide a good spark.
Don't think a coil would cause stalling though......maybe I am wrong - when was it tested/last replaced?