Well, not Toyota, but down here in BRA it is the Mercedes OM364. ->
Mercedes-Benz OM364 engine - Wikipedia - https://en.wikipedia.org/wiki/Mercedes-Benz_OM364_engine
It is a 4 inline diesel engine with 4Ltr displacement and comes in the standard-version of the Bandeirante just normal aspirated, but there is a stock OM364LA version with turbo and intercooler and 140hp (out of a truck, but it can be retrofitted as well). The problem is the low RPMs, means, the gearbox or diffs need to modified.
But it is a very simple, straight forward, comercial vehicle diesel engine build for small trucks, agriculture machines, etc. The precessor (OM314, I've it in mine Bandeirante) was also used in the early Unimogs. It's a DI engine, starts always without glowing, etc.
I get my parts from my local truck-parts-dealer and those are really affordable. A oilfilter is like 3-4USD, fuelfilter even less, everything on this engine they have on stock. I was asking for a ventilator -> "the plastic one, metal one, 6 or 8 blades,..." All in stock.
There are 2 wires to the engine: Oil Pressure Indication and Water Temperature Indication.
The little mercedes trucks make like half a million miles on this engine, then it get's overhauled. No real design-problems known. Just make sure, there is enough oil in the engine.
Downside: It is a rough engine and it feels like a real little truck, not like a car. My girlfriend loves our Jipe, but don't want to drive it because of that. And we are not speeding with it. On the highway this means, we are slow, but on rough streets or even a little offroad, it's perfect, just little above idle and it pulls you out everywhere. There is a phrase here, which is something like: "It's harder to stop the engine once it's running, then vice versa"
