The injection engine is designed for high-grade gasoline, which is rarely found at our gas stations. In addition, different injection systems have their own specific features, they must be taken into account when operating the car. And there are many such systems on our market: mechanical - K-Jetronic (KE-Jetronic), electromechanical - L-Jetronic and electronic - Motronic, Lucas, Magneti Marelli.
Many systems have two modes of operation: main and emergency, used when one of the sensors fails. The driver may not notice such a problem: there is no corresponding warning lamp on the instrument panel, and the engine continues to run (but not optimal). This often happens on cars Audi, equipped with engines with central fuel injection. About a third of motorists who have such cars do not even realize that they are driving in emergency mode. And this leads to increased fuel consumption, reduced power, uneven engine operation and difficult starting. A malfunction is detected only during the next maintenance. Therefore, on «weak» places of injection systems that manifest themselves in our conditions, it is worth dwelling in more detail.
Mechanical injection systems
They are more subject to wear and tear than others. The fuel pressure regulator usually fails after 80–120 thousand kilometers (noticeably worse engine start), injectors - after 60–80 thousand km (uneven engine operation, increased fuel consumption). Injector failure is especially insidious, as it is not immediately noticeable. Diagnostics and repair require special equipment.
The sore point of systems with electromechanical injection is air leakage through numerous vacuum hoses, which tend to crack after 4-5 years of service. Especially on cars BMW and to a lesser extent on Audi. It is quite difficult to determine such a defect.
Electronic injection systems
They have their own problems. For example, «sat down» battery, and out of old habit you decided «light a cigarette» from another car. As a result, the electronic control unit of the injection system fails. And the use of leaded gasoline, in turn, renders the oxygen concentration sensor unusable (Lambda probe) and a catalytic converter.
In general, both mechanical and electronic injection systems have their pros and cons. Mechanical ones often fail fuel pumps and dispensers. Electronic fuel pumps are more durable and cheaper, but the elimination of any malfunction of the electronic control unit will be very expensive. In addition, we, alas, have more reasons for the failure of any system than in Europe: low-quality gasoline, dirt on the roads and chemicals that are sprinkled in winter. Therefore, it is worth listening to the recommendations of experts. If possible, pour a special preparation into the tank to remove moisture from the fuel lines at each refueling; every 10,000–15,000 km of run, do a complete flush of the injection system.