86 accord/rough idle in drive at stop

I have just purchased a 86 accord (150k miles) that has been sitting for
about a year. It gets a vibration when I am at a stop and have have the
gear in drive, if I shift to neutral the vibration goes away. It idles at
750rpm in drive and about 1000rpm in neutral. What could be causing this
vibration?

 

4 clyder cars alway vibrate unless you go for a v6,my 05 car(not
Honda)do that too,a 20 years old Accord with cabuator doesn't help
either.

 

89 civic with 220,000 miles has constant vibration lately. I think
it's the
weather. The weather has been cold and chill and raining in past few
days and
my car has been vibrated about first 30 min driving. Usually on hot
day, the vibration
stop after few min driving.

 

May need a tune up. Try changing plugs, rotor, dist cap, air filter.
Also change out trans fluid. Use honda trans fluid.
Heard if non-honda brand ATF fluid is used, may cause extra friction and
vibration when in D, at idle speed.