1993 Acura Integra Shakes.

I recently test drove a 93 Acura Integra, has approximately 222000 miles.

The engine runs/sound relatively quiet and the car has had some significant parts replacements that include: new radiator, brakes, bearings, thermostat, water pump, timing belt, catalyst, starter and tune up.

Its starts right up/cuts right off without any issues. However, when the car is in drive and stopped per say at a red light, while idling it begans to ""SHAKE."

What might be causing the shaking? (It only shakes while idling in gear, not when in park).

I'm considering buying the vehicle, but want to be sure I'm not getting stuck with a major issue.

Please advise.

Thanks,

G