I have a Hilux 1993 with the original 2.5 liter diesel engine. Last year the engine was totally rebuilt and the results were good, except the garage did not do two things I asked them. First, they did not replace the cylinder sleeves (cylinder liners). Second, they did not install a new oil sump pump. My question is, do you know if the cylinder sleeves of this engine can be changed or is it a bore-in-the-block type? I am of the opinion that now after less than a year's usage of the new engine I may need to have it rebuilt again as it's smoking too much black smoke for my taste, even though I am very particular with oil change intervals and buying only good quality engine oils. This truck is used for long distance driving only with no or little load, on mostly flat terrain.

 

Black smoke on a diesel is from being over fueled. Check/clean/replace your air filter, If that does not help, you may need to get your injection pump checked/timed/calibrated. Very few Toyota diesels in the U.S.A.

 

Black smoke is definitely fuel related. If it was water, it would be white smoke. If it was oil it would be blue. Sounds like either the timing is off or the pump got cranked up a bit. Try replacing the fuel filter too and filling the new one with seafoam to clean the injectors.