Not Complete combustion = black exhaust when the car on slowly? on 2007 Dodge Grand Caravan

At last my dodge grand caravan car cant accelerate at high speed and stooped suddenly,it was a fuel pump problem now i have a new one and the car worked good but now i have a black exhaust at slowly (with no acceleration)i thought it may be a nozzle problem or something else so i ask here for help...

Asked by for the 2007 Dodge Grand Caravan