VR Running rich on idle - also idles rough

[Bizmark]

Had my VR checked for vac leaks and compression, both tests came up with good results. Though the mechanic noted that it runs rich on idle (you can smell rich exhaust fumes if you leave it idling for a while).

It also idles rough enough to vibrate the car, and some movement can be seen on the rpm gauge on idle.

The bellmouth has been removed but everyone who's looked at the car said that removing the bellmouth wouldn't cause it to idle that rough. I doubt it would have caused the car to run rich on idle.

Could the two issues be caused by a faulty sensor?

EDIT: Forgot to mention that the car apparently leans out ok under load.