1991 Cadillac Deville black smoke from exhaust

[quote:f9b6d3b10b="pam pendleton"]Other Category problem
1991 Cadillac Deville V8 Wheel Drive Type unknown Automatic 176577 miles
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Where is the fuel pressure regulator & heater control valve located?[/quote:f9b6d3b10b]

black smoke is carbon thats has built up over time, take it to the highway and stomp it to the floor and clean it out, then get a top engine clean