There the study object is the single-section RPE of VAZ-311 type. The purposes are to study the influence of unsteady regimes, which are created by the opening of flaps, at the diverse combination of adjusting and operating factors on the dynamics of change of torque, to find the causes of these influence. The developed mathematical model, the fullscale experiments allowed to obtain the data about the change of torque, to ascertain the causal and effect relations hips and to determine the ways to improve the dynamic and toxic characteristics of RPE during the acceleration for the first time. The obtained data are useful during the designing, suring the operational development of RPE of vehicles and allow to optimize the characteristics of accelerating pump at the designing stage. The study results are used in the Special Design Office of RPE, Joint-Stock Company "AvtoVAZ"Available from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio