Erratic timing indicated. Mine looked very similar to what your video shows. Take off your crank angle sensor and check the condition of the pin that drives it. There is a problem of misalisgnmenmt that affected early 90 Z32s but even latter years the pin may wear eventually. This link describes the effects and cure for a worn pin. I just did this fix and my timing is now dead nuts and my car runs better than it ever has. I have not smog tested it yet but I am anticipating it will pass.
If you search this site you will find images of what the pin looks like when it is worn and what a new one should look like
