1991 Camry Runs Rough at low rpms

We're having a similar in a.a.toyota. Check the air tube from the air filter to the intake plenum for leaks, and check for leaking/plugged vacuum lines. These are the easy things.

When was plugs, plug wires, rotor, dist cap, pcv, air filter changed out?

Also check throttle body for build up of carbon and gunk. Clean out with throttle body cleaner. Check/unclog hose & pipe that goes to EGR.