361 Woes

MOPARJ,

If had to hazzard a guess (which is all we can really do over the net :-s) I would say that a ring has frozen in the land. It could be due to the flucuating temps this time of year (your location isn't posted) combined with condensation and extended idling time.

A valve seal would leak at idle and clear out on acceleration as vacuum will drop. Do a compression test, or better yet a leakdown test and post your results.