1999 volvo rich

Black smoke is rich mixture, so something is wrong with the fuel management system. Get is connected to a pro grade scan tool computer and check long term and short term fuel trim. Check for fault codes on sensors.

https://www.google.com/search?q=volvo+xc90+d5+black+smoke

..

what kind of vehicle is it? usually black smoke means it is running rich .meaning it is burning to much fuel. carburetor needs adjusted or if is fuel injected you make have to take it to a shop to have it set there.

here try review this.
Car Exhaust Advice Good Smoke vs Bad Smoke

Black smoke indicates a rich or too much fuel condition. First thing to check is the fuel pressure regulator on the injector fuel rail. Pluu the vacuum hose off and look for signs of fuel in the vacuum hose. They will rupture the diaphragm and suck fuel in to the intake. Can also be caused by a faulty 02 sensor, bad MAF sensor or bad coolant temp sensor. If the check engine light is on check codes and post the codes.

Hmmm...maybe piston ring failure, valve seal failure, rich air/fuel mixture or maybe a head gasket (however that is normally white smoke due to coolant burning instead of oil). If it's so dark that it's almost blue then I can tell you that somehow oil is getting into the cylinder and burning alongside the air and fuel. Your best case scenario is that the engine is running rich (Rich:Too much fuel, Lean:Too much air) and the smoke is a dark grey to black color. CAUSES OF SMOKE

Smoke can be from rings worn out, cracked piston, valve guide seals if smokes at start up then stops, fueling issues if fuel is to rich but that smoke is usually black, also if head gasket is blown or head is cracked water burning turns into steam which looks like white smoke. This can also be why won't start just turns over.

turbo¿¿

could be but not prob not any check engine lights black smoke indicates it is running rich (more fuel than air) i would lean towards oxygen sensor . engine codes would be the place to start

Is there a question here ?
Are you refering to smoke coming out of the exaust ? Engine compartment ?

Please clairafy..

Thank you..

you never said if it was oil on plugs or just black soot two faults if its oil engine may need replaced if its black soot chances are your fuel mixture is to rich this would cause the car to have a heavy fuel consumption hope i have helped you