This is my update to the typical issue, talked about (by me) at this thread

fixed it.
I replaced the oil sender (cracked the old one off, of course, turns out that special socket was a waste of time, used big pliers)

Then upped my idle speed just a bit. (which was a edit to do, as it's impossible to get in there. read on here to 'tap' the lock nut. I used a screwdriver and hammer to get it loose, then stuck a nail in the bolt and worked hard to turn it)

and things are good. I think the engine was confused by my veg oil fuel and struggling to idle with the slicker fuel.

anyway, when I finally got to it, it wasn't any big work at all. probably 20 minutes total.

Cheers,
Tys