Jim S. wrote
I could entertain the notion that vapor lock or air introduced into the
system was involved, but I can't come up with a scenario where the
engine ran great all summer and then acted up on cool days down in the
fall. The conditions for vapor lock aren't intermittent to my
knowledge
- not there on a hot day, kicking my ass on a cold day.
If you are pretty sure you were running 300 rpm LOP
(sounds like a lot) then the cold temps could well be pushing it over the
edge. All else being equal, an engine will run leaner when the air temp is
lower. I have no clue as to why it is lean to begin with
though.
Tracy