"Poor mixture" - what is it? Causes of education, consequences

In order for the car to work well,the engine needs good nutrition. In order for the combustion chambers to produce an explosion of the required power, the mixture of fuel and air must be of high quality. Sometimes it is prepared with deviations in one direction or the other. This is a poor mixture, or vice versa - rich. What is it, what causes poor fuel mix, symptoms and how does the engine work? Let's try to answer these questions.

The process of mixing in car engines

In ICE combustible mixture of the required compositionIt is prepared in carburetors or in the case of an injection fuel system - it is calculated by electronics. A mixture where 15 kg of air is used for 1 kg of gasoline or other fuel is considered normal. In this mode, the engine works quite economically, while its power is at a high level. To save the amount of air in the mixture increase. So, the lean mixture is when up to 15-17 kg of air is used per 1 l of gasoline. Fuel consumption becomes minimal, and power loss is only 8-10%. The poor mixture is when there are more than 17 kg of air per 1 l of gasoline. At such a composition, the motor is unstable, a large amount of fuel is consumed, power is reduced. It is harmful to the power unit. In addition, this phenomenon often leads to omissions in the ignition system, the delay when you press the accelerator pedal.

Also, the motor can change the sound of work and willwork unstable. In injection units that correspond to Euro2, a lambda probe is installed. It controls the quality of the fuel mixture supplied to the combustion chambers.

Why the mixture becomes poor

Injection car owners know that withthe help of the computer and the corresponding settings in the firmware of the power unit can independently change the ratio of air and gasoline vapors, that is, change the fuel mixture. Many people think: the motor works automatically, and that is good. However, most owners of injection cars forget about the balance. Sometimes a poor mix is ​​made. Why does this happen? There are various reasons for this.

The main signs of depletion of the fuel mixture

The main symptom by which it is determined thatthe car is running on the wrong composition, - the engine, which constantly stalls. With a very small amount of gasoline vapor in the mixture, the spark generated by the candle simply cannot ignite such fuel. Another sign - the car in the process of movement twitches, if not moving at all in jerks. Sometimes these symptoms can talk about other faults. Therefore it is worth checking out other systems.

О том, готовится ли бедная топливовоздушная a mixture can be understood by candles. But this is relevant only for injection units. If they are brown, the engine is in perfect order. If the candles are white or light - then there is a lot of air in the fuel composition. If there is a dark soot on the element, this indicates a lack of air. However, soot is not always the right indicator of the wrong mixture. In the case of an incorrect ignition timing, the color of the candle does not correspond to normal. If a lean mixture is supplied to the engine, the owner of the car will hear characteristic claps in the muffler. When just a poor mix, he will shoot like a machine gun. If on the contrary, the fuel composition is too rich, the explosions will be single and short. And finally, the most accurate sign and method of diagnosis - is to check the exhaust gases using a gas analyzer. If the engine is operating in the wrong mode, this will also be reported by the on-board computer or the diagnostic system. There is an error in the list of errors of modern ECUs - a poor mix. It is designated P0171.

The consequences of operating a lean engine

In general, the consequences are not so much.The engine will choke when working at idle. There is also a serious risk of overheating - the fuel mixture burns much more slowly than necessary. The engine will be difficult to gain momentum under load. In the most serious situations, when a poor mixture is supplied for a long time, the engine is overheated, which in most cases leads to valve burnout. And this is a serious repair cost.

Also among the consequences can be identified hugefuel consumption. It increases due to difficulties in the process of revolutions. Therefore, owners of cars with such problems are advised to drive in low gears.

The reasons for the preparation of poor mixture

There are several typical reasons why the fuel mixture is prepared incorrectly. All these reasons can be divided into a large volume of air and a small amount of fuel.

Poor mix errors can oftenoccur in the case of a large air supply. In this case, it is recommended to check the fuel consumption sensor - very often the sensor channels are contaminated. The second reason is a vacuum leak. The third is an EGR valve that draws in additional air. The valve may be broken or closed loosely. If a poor mixture enters the cylinders, the causes are injector, ignition, fuel system, disturbance in the operation of the gas distribution system.

How to check the EGR valve

To test the operation of this valve, firstit is dismantled and then checked. The test can be carried out using a jet of compressed air. Air is fed into one of the holes - the valve should work. You can see this at the top through the hole. The valve is clogged due to the presence of dirty air. On the nest or plate element carbon deposits are formed. The valve is wedged, and as a result, the wrong and often too poor mixture is prepared.

DFID sensor

Sometimes you need to check everything you can.It should start with the diagnosis of sensors. As you know, one of the most popular problems is a clogged or clogged air flow sensor. If a large amount of dirt has accumulated on it, this often leads to a slow response of the ECU to air flow and its replacement. Additionally, the sensor may be contaminated by fuel fumes that pass through the intake manifold. In addition, plaque can accumulate through the throttle body when the engine is not running. A layer of paraffin is deposited on the sensor, due to which incorrect data on the proportions of the fuel mixture fall into the computer.

Then comes the situation when the control unitmotor can not add to the mixture the right amount of fuel (the amount of air is already quite large). And then an error appears on the sensor display - poor fuel mixture.

Faults in the intake system

To eliminate the problem of lean mixtureIt is also recommended to diagnose the throttle. The position of the flap should clearly correspond to the accelerator pedal position. If the throttle is automatic, it is important to ensure that its position matches the temperature of the power unit. On a hot engine, it must be fully open, on a cold one - turned at a certain angle. If the damper is open, then the air damper control system is faulty. What else is wrong if a poor mixture forms in the motor? Causes - Injector and damaged intake manifold gaskets. To eliminate this problem, it is recommended to tighten the manifold, and if necessary, replace the gaskets.

Problems with timing

To the gas distribution mechanism did not affecton the depletion of the fuel mixture, it must be checked. And if necessary - customize. When examining the gas distribution mechanism, special attention is paid to the tension roller and the belt (its condition and marks). If the drive is chained, then check and chain together with the tensioner system.

Fuel system

Проверки топливной системы будут отнюдь не superfluous. It is important to check the performance of the injectors, but this can only be done with special equipment. Often, the majority of problems with nozzles are associated with poor-quality gasoline - then you can get rid of simply flushing these parts.

Then check the level of fuel pressure andperformance of the fuel pump, if any, in the system. On the pump, check the voltage. Among other things, check the fuel pressure regulator and fuel filter.

False errors

It happens that the system along with the mistakes of the poormixes and other codes. For example, p0100 or p0102. It is immediately apparent from them that the reason is in the sensor. To solve the problem, you must clean the sensor. For these purposes, it is recommended to use special tools for cleaning electrical appliances. But it is better to still replace.

Depleted codes

Do not think that if an error occurred“Poor mix”, only one code reports the reasons for this. For example, P0171 is standard, but for Ford cars this cipher reports problems in the first cylinder. In some models from Honda, an error P0172 may appear, which reports a poor mix.

On popular Chevrolet Captiva problem withthe mixture is denoted differently - P2177. But to eliminate the need to use universal methods. On the Japanese car Mazda-6 appears code 2178, which also indicates a poor mixture. All this is determined by the method of computer diagnostics.

Repair as soon as possible

It should be remembered that if the engine is longtime exploited with such problems, this can significantly reduce its resource. Depleted mixture can cause premature failure of a huge number of different components and assemblies. In this case, the repair will be much more expensive than if in time to perform diagnostics and eliminate the malfunction.