In the present study, an improved multidimensional numerical code has been used to simulate the combustion and emission formation processes of direct injection diesel engine. Soot formation and oxidation processes have been modeled according to a hybrid particle turbulent transport controlled rate and soot oxidation rate expression. A reasonable agreement of the measured and computed data of in-cylinder pressure, heat release rate, NO, and soot emissions for different engine operation conditions has been made. The effects of fuel injection pressure and timing on the diesel engine combustion and emissions formation have been further computed based on an improved multidimensional combustion and soot model. The effects of different testing conditions on the gaseous and particulate emissions have been discussed. Predicted trends of soot and NO formation have also been presented together with the corresponding measured data. It has been demonstrated that the developed multidimensional engine combustion and emission formation model has provided good insight for new designs of different engine parameters and in-cylinder engine events.