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 that must be taken into account when operating the vehicle. There are quite a few such systems on our market: mechanical – K-Jetronic (KE-Jetronic), electromechanical – L-Jetronic and electronic – Motronic, Lucas, Magneti Marelli.
Many systems have two operating modes: main and emergency, used when one of the sensors fails. The driver may not notice such a malfunction: there is no corresponding indicator light on the instrument panel, and the engine continues to run (but no longer in optimal mode). This happens quite often in cars Audi, equipped with engines with central fuel injection. About a third of drivers who own such cars don't even realize that they are driving in emergency mode. This leads to increased fuel consumption, reduced power, rough engine operation and difficult starting. The malfunction is detected only during routine maintenance. Therefore, it is worth dwelling in more detail on the "weak" points of injection systems that appear in our conditions.
Mechanical injection systems
They are more susceptible to physical wear and tear than others. The fuel pressure regulator usually fails after 80,000 to 120,000 km of mileage (engine starting is noticeably impaired), injectors - after 60-80 thousand km (uneven engine operation, increased fuel consumption). Injector failure is particularly insidious because it may not be immediately noticeable. Special equipment is required for diagnostics and repairs.
The weak point of systems with electromechanical injection is air suction through numerous vacuum hoses, which tend to crack after 4–5 years of service. Especially on cars ВМW and to a slightly lesser extent on Audi. Identifying such a defect is quite difficult.
Electronic injection systems
They have their own problems. For example, your battery is dead, and out of habit you decide to jump-start it from another car. As a result, the electronic control unit of the injection system fails. The use of leaded gasoline, in turn, renders the oxygen concentration sensor unusable (lambda probe) and a catalytic converter.
(Text taken from an online platform MazBook)
In general, both mechanical and electronic injection systems have their pros and cons. In mechanical engines, fuel pumps and distributors often fail. Electronic fuel pumps are more durable and cheaper, but fixing any malfunction of the electronic control unit will be quite expensive. Moreover, unfortunately, we have more reasons for any system to fail than in Europe: low-quality gasoline, dirt on the roads, and chemicals that are spread in the winter. Therefore, it is worth listening to the recommendations of experts. If possible, add a special product to the tank each time you refuel to remove moisture from the fuel lines; every 10,000–15,000 km, perform a complete flush of the injection system.