The injection engine is designed for high-grade gasoline, which is not often 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: with mechanical injection "K(KE)-Jetronic", electromechanical "L-Jetronic" and electronic ones – "Motronic", "Lucas", "Marelli".
Many systems have two operating modes: main and emergency – when one of the sensors is faulty. The driver may not even notice such a malfunction: there is no alarm signal on the dashboard, and the engine continues to run (but no longer in optimal mode). This often happens in the "Audi-80" with central injection. About a third of car enthusiasts 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. The malfunction is detected only during the next maintenance. Therefore, it is worth dwelling on the "weak" points of each system that appear in our conditions in more detail.
Systems with mechanical injection. They are more susceptible to physical wear than others. The fuel pressure regulator usually fails after 80-120 thousand km of mileage (engine starting becomes noticeably worse), injectors - after 60-80 thousand (uneven engine operation, increased fuel consumption). Injector failure is especially insidious because it is not immediately noticeable. Special equipment is required for diagnostics and repair.
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 BMW and, to a lesser extent, on Audi. It is quite difficult to detect such a defect.
The original can be found on this resource ToyotaMan
Electronic systems have their own problems. For example, the battery is dead, and you decide to jump-start it from another car. As a result, the electronic unit breaks down. And using leaded gasoline, in turn, will render the lambda probe and catalytic converter unusable.
In general, both mechanical and electronic injection systems have their pros and cons. Mechanical fuel pumps and distributors fail more often. Electronic fuel pumps are more durable and cheaper, but any computer malfunction will be expensive. In addition, there are, unfortunately, more reasons for the failure of any system in our country than in Western Europe or America: low-quality gasoline, dirt on the roads and chemicals sprinkled on them. Therefore, it is worth listening to the recommendations of specialists. Try to use imported gasoline, if possible; to remove moisture from fuel lines, pour a special preparation into the tank every time you fill up; every 10,000–15,000 km, perform a complete flush of the injection system.
Another feature: any failure is recorded by the computer. And even after replacing the faulty part, it will issue incorrect commands - until the failure is "erased" on a special stand.