1996 auto engine emit black smoke lost power in steep road

Depends on the colour of the smoke.
Unlikely an engine will sound healthy emitting black smoke - excess fuel.

An engine could sound healthy emitting white smoke (steam from coolant) but not from white smoke (excess unburned diesel).

Most engines emitting blue or blue-grey smoke from burning engine oil can sound very healthy.

Black smoke means the vehicle is running really rich , do you know what that means ? lacks power when accelerating could be plugged catalytic converter . Fouled spark plugs . Leaking , fuel injectors , fuel pressure regulator leaking .Air filter clogged .Hooking up a scan tool an checking fuel trims , seeing if the computer is taking fuel away or adding .Seeing what the computer is seeing
Why black smoke coming from my car engine Troubleshooting 1 Must Watch

run the fault codes and look for a faulty TCM unit . It is not registering an engine rpm change to change the ratio in the transmission

Sounds like the engine is unwell.

Black smoke suggests that engine oil is getting into the combustion chambers.

This could be the head gasket has blown a hole, or that the piston (liners) are worn which would probably mean a new engine (rather than a rebore, which I doubt people do much these days).

Isuzu Troopers were underpowered, I read on the wikipedia page, so I guess that the engines may tend to wear out.

If it is the head gasket, then it could be repaired fairly cheaply. A mechanic would be able to tell the difference from the noise that the engine makes. I can't say I have ever heard an engine with worn pistols but someone told me one can hear them "slap"
http://www.pistonslap.com/whatisit.htm

If you are really lucky then it might be a hole in the exhaust before the silencer, which could also affect the power but I am not sure why there'd be black smoke. If it were an exhaust problem then there would be a loud noise from the exhaust too.

Clean MAF , Replace TPS . Use fuel injector cleaner in tank .

HI do you now the color of the smoke
if engine emits white smoke its not burning the fuel
it could be water mixing with fuel = head gasket even tho you
dot have water in the oil
if engine emits black smoke - that's excessive fuel to air ration
check air filter & air inlet to see if clogged
if engine emits blue smoke - excessive oil consumption
cloud be valve seals

Sounds like injectors are plugging up. Run a bottle of Diesel fuel system cleaner w/your next tankful. It might take two times but injectors get gummed up easily.

Black smoke indicates no air, check your air filter, if you have done that and it is ok, check the PCV valve. Thats about all that I can suggest. Hope that helps.

If it is a white colored smoke,then it is most likely coolant,being burned.Ahead gasket most likely has blown.If it is black smoke,test would need to be done to diagnose the problem.

Yes , power steering fluid will smoke if it gets on a hot engine, especially on any part of the exhaust system. Barring anything else wrong with the engine such as a coolant leak, and the engine running OK otherwise, I would say that the smoke is from power steering fluid dripping or getting blown on the exhaust by the fan.