tried searching the forum, but maybe the idling pattern is recognizable and someone will be able to give me a shortcut where to look for an issue.
service history of the car is unknown, changed oil, filters, transmission and brake fluids. planning to replace all the ignition components (plugs, wires, distributor, ignition coil, etc..) are to be replaced to address the issue.
hot or cold engine seems to have same idling. sometimes rpm stabilizes at 1k rpm and hold there, but rarely.
video here:
https://youtu.be/WNyRnYqqMSM