Well, for example, due to a knock sensor breakage, throttle sensor wear, an incorrect oxygen or temperature sensor signal, in the worst case, fuel consumption will increase and the engine will become sluggish. Even the color of the Check engine is yellow, warning, and not at all red, like the lamps, which can not go on when lit. However, people are still scared and continue to arrive “on a tie” because of this indicator.
The irony is that most defects do not cause the Check engine to catch fire - the controller simply cannot identify them. Let's say there is a deviation in the readings of the mass air flow sensor (DMRV). The car is getting dumb. There is a signal, but the fact that it is incorrect cannot be determined by the “brains” of the engine. Only the brains of the diagnostician can understand this, and even then not everyone. The sensor is expensive, about $ 100, but extremely moody. Fails due to dust and oil pollution from crankcase gases entering the inlet pipe. Moreover, even the thinnest film of oil is enough to turn the ride into a screech, if you pour oil on it (this happens on the “shifters”) it will fail. Hence the moral: at each MOT, check the health of the crankcase ventilation system, buy an air filter only of high quality, always reinforced with a metal mesh *.
The controller is not able to determine the wear of the fuel pump. The symptom is the same - sluggish acceleration (especially in high gears). The abrasive particles are most often to blame for in the mixture of hydrocarbons, which, for our misunderstanding, is called gasoline. (I happened to change the gas pump in a car with a mileage of about 10, 000 km, the tank of which was full of sand and … pebbles!) If the gas pump has to be changed, it is better not to skimp and buy a branded one, because the pumps from Vladimir have a bad habit of jamming.
But what about the fuel filter? - you ask. But in no way: both the grid of the gas intake and the fine filter (which also needs to be changed on time) cannot hold all mechanical particles. So these very particles do their dirty deed **.
Another control unit will not say a word that it is time to change the candles. He cannot turn them out - unfortunately … Domestic gasoline is full of iron-containing antiknock agents, because of which candle insulators are covered with a reddish coating. Then they have one way - to the trash can. Therefore, I recommend changing candles after 15, 000 km without hesitation. Not necessarily well-known manufacturers - VAZ engines work fine on inexpensive ones, for example Brisk.
Separate song wiring injection system. If we talk about the VAZ design, then in general it deserves all praises: high-quality connectors, wiring harnesses in a protective sheath. But does it happen that we have a fly in the ointment? I do not know what the Togliatti engineers were guided by laying the length of the wires on the temperature sensor. A slight negligence during assembly - and a tourniquet in a thick finger hangs on the poor fellow. On new (and not only) cars, it is better to immediately increase the sensor wires. At the same time, we will check whether the tie rod harness is touching: a sort of time bomb.
The control unit on the Lada itself is reliable. They burn it, as a rule, in car services! Oddly enough, often painters and welders have no idea that when welding it is better to remove the connector from the unit, and if the car is placed in a drying chamber, then the "brains" must be removed completely!
In a word, there is nothing wrong with the injector. Know to change the timing belt on time (especially on a 16-valve engine), refuel with high-quality gasoline, service it - and don't be afraid!
* In my opinion, a notorious optimist indicated on the filter housing: “replacement every 30, 000 km”. It may be that he will serve this term in asphalt megacities, but it is better to change it after 12, 000–15, 000, especially if the car is operated only in the summer. It’s easier to change the 150-ruble filter once again than to ditch the DMRV at a cost of almost 3 thousand.
** It is advisable to leave at least 5–7 liters of gasoline in the tank of the injection vehicle, it is bad if it is not at all - then the pump is wearing out at a catastrophic rate. If the car began to rapidly lose power, and soon completely got up before going to the service, try to refuel it. Are you laughing? And about once a month, cars with the diagnosis "empty tank" are delivered to my service. Do not look at the fuel gauge - it is cunningly evil … Never pour anything into the tank except gasoline! No one can vouch for the contents of bright bottles with all kinds of "cleaners of fuel systems." And it, this contents, can easily dissolve the gas intake grid! Do not believe? And I saw the grid after applying such a “cleaner”. Her pieces got inside the gas pump and jammed it. No gentlemen! Nozzles must be flushed with professionals, on a special installation.