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Fuel consumption, emissions and output power are some of the very important factors for automotive engine design. Since the combustion efficiency depends on the quality of the air-fuel mixture and mixture quality depends on the fuel injection parameters, the investigation of spray features is an overall goal in direct injection engines. In this paper, simulation of GDI spray is carried out in a constant volume chamber contains nitrogen in four different injection pressure using the AVL Fire software. The results are validated against the Istituto Motori-CNR experimental data. The log-normal probability distribution as an initial droplet diameter and Huh-Gosman model as secondary breakup were used. Then the combustion of EF7 Engine with direct injection was studied and wall film thickness was compared at different injection pressures and injector angles. Also, the effects of wall temperature and single-stage and two-stage fuel injection with different ratios of injected fuel mass were evaluated on the wall film. Since the fuel can be injected into the combustion chamber in both intake and compression stroke according to engine operating conditions in gasoline direct injection engines, the simulation was done for open cycle engine.