1984 FJ60 Sudden rough idle problem... (8 Viewers)

[Ozarks4WD]

Engine was working like a sewing machine before, until last night.
But, let me start from the beginning, I installed mechanical water temp gauge on the upper radiator hose yesterday. Test it for leaks, all was good, took LC for the ride, all good, no issues. Let her sit for a while, checked for any leaks again, went for another ride - all good. No issues.
At that time, I connected light bulb in the autometer gauge to the cigarette lighter bulb wire, tested lighting, all good. Took it for another ride, gauge was working perfectly, no leaks, I'm happy. Car was sitting for few hours after that, and then i decided to park it under the car port. After short drive, when opening the gate, i noticed that suddenly LC idling is rough. I parked the car and didn't do anything else last night because it was dark already. Today i checked the engine bay, looked for maybe some unplugged wires, pinched vacuum hoses, anything wrong - all seems to be fine. There is a fuel in the carbteur window, idle solenoid is clicking and when you unplug the green plug when engine is running, engine will die immediately too. Well, without revving up, engine dies off too. See the video.
Please help...anyones has any ideas where to start "digging"?

 

[Ozarks4WD]

Ok, i have removed and cleaned and checked the gap on all sparks. Put cables back. Removed and cleaned fuel filter (it was nasty).
Took her for the spin and magically everything is back to normal...she idles like nothing happened.
Now, look at the sparks, all are looking the same. This does look like she is running little rich to you?

Also, old fuel filter

 

[OSS]

These old engines can get the spark plugs oily and then black by running the engine for short jaunts - not allowing everything to get real hot and burn crud off.
Short trips play hell on the spark plugs.

 

[Ozarks4WD]

These old engines can get the spark plugs oily and then black by running the engine for short jaunts - not allowing everything to get real hot and burn crud off.
Short trips play hell on the spark plugs.

Thank you for replying!