definitely too rich, did you check the spark plugs to see how rich it was running? also, you can get a set of cheap spark plugs to run in there for like a week or so, then take them out to see how rich/lean the car is running..... if the car vibrates when the idle drops too low, than that is normal, any car will shake when the idle is too low, but if it does it at like 1K it could be that a number or things got carbon build up from running too rich, how long has she been driving the car around like this?