In this work, the ignition of liquid fuel was studied at various rates of fuel injection into the combustion chamber. The studied processes are described by the following equations: continuity, momentum, energy, k-ɛ turbulence model and others. The computational experiment was carried out using the KIVA-II software. The numerical method is efficient and takes into account various factors such as multistage chemical chain reactions, transfer of momentum, heat and mass by convection, radiation, turbulence, etc. In order to select the optimal parameters of the organization of these processes influence of the heptane injection rate into the combustion chamber on the process of combustion and self-ignition of heptane was studied. The injection rate of heptane varied from 160 m/s to 400 m/s an interval of 30 m/s. The size and temperature distributions of heptane droplets before evaporation, the concentration fields of carbon dioxide, and the temperature fields in the combustion chamber depending on the rate of fuel injection through the injector into the combustion chamber were obtained. The optimal range of heptane injection speed was determined, which is 250 m/s - 280 m/s, in order to increase the efficiency of the combustion chamber and reduce the negative impact on the environment.