The occurrence of deviations in the operation of the power system associated with coking of the fuel injectors is possible during long-term operation of vehicles. Most often, such a malfunction occurs when the car is additionally equipped with a liquefied gas (LPG) or compressed gas (CNG) power system. In this case, the standard injectors responsible for supplying gasoline operate for a short time and cannot self-clean during operation. An analysis of the design features of gasoline injectors affecting the number and shape of fuel jets was carried out. The main mechanisms of clogging and coking of gasoline injectors, as well as their impact on the operation of spark-ignition engines, are considered. A review of methods for testing and restoring the operating condition of gasoline injectors is presented, the results of testing 12 sets of injectors before and after cleaning are given. Analysis of the results shows that before cleaning, in 42% of cases one nozzle had a large deviation; in 25% of cases, two nozzles had a large deviation; in 17% of cases, 4 injectors were outside the median value; in 17% of cases the injectors were within normal limits. After cleaning, 75% of the injectors were within normal limits; in the remaining cases, although outside the normal range, an improvement in parameters was observed, with the exception of one case where a slight deterioration was observed. In most cases, ultrasonic cleaning allows the injectors to be restored to working condition, however, in isolated cases, a noticeable difference in the injector consumption is possible, implying their further rejection and replacement.