what is causing really rough idle.
My car's transmission is unknown to me.
Rough idling engines can typically be caused by ignition system or fuel system failures. This can be things like spark plugs, spark plug wires, distributor cap, distributor rotor, the distributor itself, fuel injectors, fuel filter, fuel pump, etc. I would recommend hiring a qualified professional to test your fuel and ignition system for errors which will diagnose the rough idling. This is where the issue lies the majority of the time when the engine is idling rough.