In relation to the car the breakthrough is a short-term spontaneous change of frequency of rotation of a bent shaft of the engine irrespective of the provision of a pedal of "gas". In daily operation series of breakthroughs, as a rule, take place. A limit case of breakthrough — a failure — notable delay of response of the engine to pressing of a pedal of an accelerator.

It is conditionally possible to allocate three types of breakthroughs:

– at the time of a start of motion;

– at dispersal;

– at the established movement, i.e. at the constant provision of a pedal of "gas".

Definition of the reasons of breakthroughs at the movement of the car with the injector engine requires the special diagnostic equipment therefore we recommend to address to the car service specializing in repair of systems of injection of fuel. However, as practice shows, in most cases breakthroughs are caused by the insufficient pressure of fuel in a fuel stage or malfunction of the sensor of provision of a butterfly valve.

With some skills the reason of breakthroughs can be defined independently.