I recently acquired an Econovan 08/99 with a Mazda built engine JC0AAASGMEXS37798 (VIN number lookup comes up as invalid btw). Engine Family is ACE-FE. There is what I would call normal pattern of oil burning for a worn engine that's had a hard life - after a long downhill run there is a puff of blue smoke but not much otherwise during normal use - not a lot of oil used.

But when cold there is either little or no apparent smoke if allowed to idle only then driven but a lot of smoke if the engine is revved. The smoke doesn't start immediately and every time it starts (which I would think would be the case for oil draining through worn valve seals) and it doesn't clear readily once triggered by revving the engine, it gets worse when revved more, like it's sucking oil in from somewhere. It's a carby 1998cc engine with all the worst of the complex pollution reduction gear that came prior to fuel injection, with (to me) unidentifiable bits and pieces with hoses everywhere. To find that this problem is solvable without an engine rebuild would be very good news.