Vacuum is highest under idle and DECELLERATION. If indeed you are seeing smoke at idle and/or decelleration your pulling
oil in from some where.
Decellerate, come to a stop, and that deep vacuum sucked in the
oil your seeing while you sit idling. Trying coasting to a stop with the clutch in and see what happens.
Ernie
EDIT: Vacuum is near zero under hard accelleration!