Ok, I'm back with some more results I suppose
This weekend, I pulled all 6 injectors and cleaned them, and also all 6 plugs and replaced them.
Car idles much much better than before, but still not in driving condition.
It cranks up pretty good, when cold you have to feather the throttle a little and it may die on the first start up.
If you lightly give it throttle, it will rev flawlessly to 3-3500rpm. As soon as you give it more throttle, it starts backfiring / fluttering/ dying. It's like it's not getting enough fuel for the amount of air being ingested.
When under load, in a gear, it's gutless. The fastest I can go uphill is maybe 2-5mph. Downhill, 30mph.
https://youtu.be/gQBwrDfDok8
Could the pump be clogged from the nasty fuel?
My next two missions are to replace the pump and inspect the tank strainer in the bottom.
Any tips?