Sprinter 313 black exhaust smoke

Your van has a 4G60 series(62/63/64) engine, and is now 25 years old. Loss of power can be caused by many things at this age. Most likely is worn valve stems, leaking valves, and loss of compression. Could be a failing head gasket. The first step is do dry and wet compression test, then a leak down test. If there is a lot of blue exhaust smoke, the engine is burning oil (worn head or/and piston rings). If there's white smoke, its burning coolant, and you have a blown head gasket.

Assuming the rest of the van is adequately mechanically sound, the best approach is likely rebuilding the engine with new rings, possibly rebore for oversize pistons, and a re-manufactured head.

you might have a hole or a blown gasket on the exhaust system

black smoke is over fueling and although the turbo appears to spin ok the vale variation actuator may not be operating correctly
there are vanes in the exhaust turbine housing that are altered to increase the exhaust gas flow onto the turbine blades for quicker acceleration and these vanes are operated by a vacuum actuator and rod by a sensor
the vanes are subject to extreme heat and can rust stuck open or the hose gets hard and cracks
s not allowing the vanes to work
I would be concentrating in this area before the EGR valve
run the fault codes as well to get a better idea of the possible fault as some systems only put the light on for extreme conditions in engine and transmission

As a general rule black smoke is soot from excess fuel, white smoke is either steam or a great deal of unburned fuel (mainly diesels) and blue or blue/grey smoke is burning oil.

A trail of sooty smoke would indicate too much fuel is entering the cylinders. Perhaps you have a dribbling injector or a faulty sensor or perhaps your injectors are old and worn with bad spray patterns.

Black, sooty smoke? Lacks power? Coughs and hesitates under load? Hunts at idle? Lousy fuel consumption? It's running rich.

check door switches

hi,
I've the same probem, it's been 'fixed' twice in the cars life but re-occurs.
I believe the throttle body gets 'gunked-up' possibly due to a faulty solenoid or sensor.
I don't have a full solution but will post when I do.

Sounds more like an O2 Sensor or just a coincidence that you lost a seal or something that is allowing oil into the exhaust. The Smoke tells me it's oil in the Exhaust as in most cases with an O2 sensor you would just get an odor of Fuel because it was flooding.

which is standard or the best motor oil for HDI?

if the charge air hose to the intake splits it can cause this condition also.