Injection process control for internal combustion engines ensures optimal operating conditions regardless of engine load conditions or environmental conditions. Optimization of the injection process has a major impact on the efficiency of engine processes by increasing engine power and torque, reducing fuel consumption and pollutant emissions. This paper proposes a numerical analysis of the injection process by modeling and computer simulation of single-cylinder engine 5402 AVL, based on multiple fuel injections. To achieve the proposed objective, the virtual model for the AVL 5402 experimental single-cylinder engine was created in the AVL Boost simulation application, model for which the AVL MCC combustion model governed by the iRate injection law was implemented. In order to achieve the proposed computerized simulations, the developed studying methodology is based on the division of injection process into multiple sequences, starting from a well-defined amount of fuel for each engine speed and load value. In the first case, the engine functionality is monitored in the case of an injection process consisting of a pilot injection and a main injection. In the second case, the engine functionality is monitored in the case of an injection process consisting of two pilot injections and a main injection. In the third case, the engine functionality is monitored in the case of an injection process consisting of two pilot injections and two main injections.