Could be a rich mixture. Error P0172 - Fuel system too rich. Checking and eliminating causes

Everyone knows that a car engine does not run on pure gasoline, but on a mixture of gasoline and air, the so-called fuel-air mixture. It is calculated that for the complete combustion of one kilogram of gasoline, fifteen kilograms of air are needed, that is, the optimal composition of the fuel mixture is approximately 15/1 - one kilogram of gasoline per 15 air. At the same time, the power and economical indicators of the engine will be normal (balanced).

Reducing the proportion of air causes an enrichment of the fuel mixture. Permissible, within the proportion - 13/1. Such a mixture is called enriched and is necessary for the engine to operate at full load in order to fully unlock its power potential.

Reducing the proportion of air to less than 13 kg per 1 kg of gasoline leads to the formation of a rich fuel mixture. A rich fuel mixture, unlike an enriched one, leads to a decrease in engine power and throttle response, since gasoline does not burn completely due to a lack of oxygen.

At a ratio of 5/1, the fuel mixture is considered over-enriched, and the engine refuses to work on it at all, gasoline simply does not ignite.

Either the carburetor or the engine management system (ECM) is responsible for the correct mixture formation specifically for each engine operating mode.

We will be interested in a rich fuel mixture, since the engine runs on it, but its work in this case leaves much to be desired and something urgently needs to be done about it.

Consider the signs and causes of the formation of a rich fuel mixture on carburetor engines of VAZ cars.

Signs of a rich fuel mixture

- Black deposits on the electrodes of the spark plugs

- black smoke from muffler

— Cold engine easier to start than hot

- High fuel consumption

- Decreased power and throttle response of the engine

The main reasons for the formation of a rich mixture

Carburetor or fuel system malfunctions:

- clogged air jets of the GDS;

- fuel and (or) air jets of the GDS, according to their calibration data, do not meet the standard for this engine;

- high fuel level float chamber carburetor;

- the economizer of power modes is faulty;

- EPHH system is faulty;

- pumps fuel pump.

Other faults with similar symptoms

Ignition system malfunctions

- too early ignition timing;

- one or more spark plugs are faulty;

- faulty armored wires, slider, distributor cover;

— the centrifugal regulator of an advancing of ignition is faulty;

— the ignition coil is faulty;

- too small a gap between the contacts of the breaker (for a contact ignition system).

Engine malfunction

— Downed valve timing (jumped timing belt);

- elements of the cylinder-piston group are worn out;

- too large gaps in the valve drive.

Notes and additions

Reading 6 min.

A rich mixture causes the injector. A rich mixture is a fuel mixture prepared with an excess amount of gasoline in the engine cylinders (injector). The reasons for the formation of a rich mixture are numerous and can be triggered by improper operation of the vehicle, as well as technical malfunctions engine systems.

As is known, in modern cars installed engines internal combustion(ICE). This means that it is not gasoline or diesel that burns in the engine cylinders, but the fuel-air mixture. It happens in the following way. The fuel injectors spray fuel, which evaporates in front of the incoming valves in the form of a fine suspension. And already in the cylinders, these vapors are burned, mixed with air from an electric spark.

Thus, the fuel-air mixture (FA) is a derivative of liquid fuel and finely dispersed air with the inclusion of a vapor phase in a small amount.

Rich TVS: concepts

Thus, the composition of the fuel mixture is determined by the ratio of air to fuel. This ratio depends on the amount of liquid fuel supplied to the cylinders. When acceleration occurs, the liquid fuel is intensively saturated with air mass. When this ratio is violated, the fuel-air mixture is rich or lean.

Cooking fuel-air mixture- This is the process for which the car's injector is responsible. The injector injection system prepares mixtures with different oxygen content, and this is what ensures the variety of operating modes of the internal combustion engine. It is the composition of the fuel mixture that allows the car to sharply increase speed during overtaking or overcome the slope.

A rich mixture is a mixture that contains less air than required and more gasoline than required. The burning rate of a rich mixture is reduced, and therefore its afterburning occurs already in the muffler. Sometimes such a mixture is symbolically called high-calorie.

There is a mathematical formula that determines at what ratio of atmospheric air to fuel, the fuel mixture will be normal, rich or lean. It is believed that the normal ratio is a mixture of 14.7 kg of air and 1 kg of fuel in liquid form. If the ratio of 14:1 is increased in favor of the air mixture, the fuel mixture will be lean. Conversely, when the ratio is 14:1 in favor of liquid fuel, the mixture will be rich.

Artificial forcing of engine power is provided by such an adjustment of the fuel supply when the amount of oxygen supplied increases. The desire of the car owner to save on fuel consumption is achieved by supplying more atmospheric air.

Poor TVS: concepts

- this is a fuel assembly with a reduced content of gasoline and with an increased content of air.

The error code assigned to this error by the on-board computer is P0171. Literally, this code stands for very poor fuel supply. Sometimes poor TVS is called low-calorie.

A lean fuel mixture gives itself out as such: very poor traction, especially noticeable on steep climbs, engine overheating, the injector makes popping sounds, white or gray smoke comes out of the exhaust pipe.

Reasons for making a lean FA: fuel pump malfunction, use of gasoline with water or other impurities, fuel gauge malfunction, vacuum hoses malfunction, or intake manifold, the injectors supply too little gasoline, the pressure sensor malfunctions.

Signs of the formation of a rich mixture

The formation of a rich fuel mixture occurs with a chic set of manifestations.

1. The first and most important symptom: the malfunction indicator lights up, issued by the car's on-board computer. Error code: P0172.
2. The car muffler makes a loud popping sound. This happens due to a lack of air in the engine cylinders and, as a result, afterburning of air already in exhaust pipe.
3. Exhaust gases are black or grey. It occurs due to the fact that fuel assemblies do not burn in the engine, but in the exhaust pipe, the exhaust gas does not undergo any purification by filters, and when burning in the pipe, the amount of atmospheric air sharply increases.
4. The car is less dynamic, less powerful. It is explained by the slow rate of combustion of the fuel mixture. As a result of the slow combustion of fuel, dips in power occur. With a rich mixture, it is even possible that the car simply will not budge.
5. Fuel consumption has risen sharply. It is explained by the inefficient consumption of the fuel mixture: the low combustion rate is trying to cover it with an additional injection of liquid fuel.

Reasons for the formation of a rich mixture

The formation of a rich fuel-air mixture occurs in the following cases:

1. Reasons directly related to incorrect operation and incorrect configuration of vehicle systems:

• as a result of improper adjustment of the fuel system in order to reduce fuel consumption;
• as a result of improper adjustment of the fuel system in order to increase power.

1. Associated with malfunctioning engine systems:

• injectors supply too much fuel;
• pollution air filter;

• gaping air damper;
• malfunction of the fuel pressure regulator;
• malfunction of the air flow sensor, malfunction of the gasoline vapor recovery system, incorrect operation of the economizer.

First aid for a car with error P0172

The first thing to eliminate if the injector is preparing a rich mixture is to abandon all sorts of additional settings for the volume of air or fuel supplied. The fuel system may have been adjusted on the vehicle. If this is the case, these adjustments must be canceled, since prolonged operation of the engine on a rich mixture can lead to piston breakdown and failure of the candles.

The second common reason for the formation of a rich mixture is incorrect fuel supply by injectors. Injectors can be suspected if there are traces of combustion of fuel assemblies on the outside of the injector. Traces of combustion of fuel assemblies can also be found on one side of the copper sealing ring. If such signs are found, it is necessary to check whether the injector is installed correctly, whether the sealing ring is in place.

The third undeservedly ignored reason is the contamination of the air filter. If the filter is heavily clogged, there is an increase in pressure in the cylinders, and as a result, erroneous preparation of fuel assemblies.

The fourth reason for the preparation of a rich fuel assembly is the incomplete closing of the air damper / valve. In this case, the pressure in the cylinders is reduced and this, again, leads to errors in the preparation of fuel assemblies and disruption of the functioning of internal combustion engines: the injectors begin to pour more fuel, increasing consumption and reducing power.

If the fuel pressure regulator does not fully function on its own, then the errors here are the same as in the previous two cases: increased or decreased pressure in the cylinders.

The sixth group of reasons is not so common. Problems with an air flow sensor, a fuel vapor recovery system, or problems with an economizer are often a consequence. However, if all previous causes have been eliminated, but the problem remains, this group of causes should be checked. If the problem is really in them, then it will be solved by an elementary replacement of these parts.

Preparing rich fuel assemblies is a very common problem, and therefore it is well known to mechanics in car services and locksmith shops. The problem of preparing bad fuel assemblies is usually eliminated quickly, literally one or two times and for little money (depending on the level of the service center and the car model).

It should be noted that 90% of errors are solved by simply adjusting the injection of liquid fuel. The main thing here is to fix the problem in time, until the injector breaks down and other problems arise: for example, pistons can become unusable, candles burn out, etc.

You will need to check:

• Are the sensors working correctly?
• whether the settings of the on-board computer have changed;
• Is the air filter correct?

First of all, you need to remember if the onboard electronic system. It often happens that the problem pops up precisely after the ECU has been reflashed.

Here, usually the power unit works fine for some time, but in the end, if the new settings do not correspond to the current ratings of the installed sensors, the problem makes itself felt. Ultimately, the fuel supply to the injector is incorrect.

In addition, there is a possibility of a malfunction in the injection system after the air intake sensor or some other sensor built into the fuel circuit has been replaced.

In other cases, when the breakdown is not related to the above reasons, it will be necessary to diagnose power unit using a computer. To do this, you will have to go to a car service.

Regulations

On average, the correct ratio of air to fuel is 15 kilograms to 1. When:

• oxygen is supplied more than normal - the mixture is called poor;
• if more gasoline - rich.

In some cases, the proportion is violated, but control over it is entirely the prerogative of the ECU, it receives data from different sensors. A noticeable decrease in fuel consumption against the background of a drop in engine power indicates problems with a lean mixture.

If too much gasoline enters the injector, then you will have to refuel more often. At the same time, there are several rather dangerous nuances - they cannot be discounted in any case.

Other signs

Of course, there are many reasons for excessive fuel consumption. But usually the code P0172 is the first sign here.

There are also a number of other signs of a problem:

• loud bangs are heard in the muffler;
• smoke from the chimney is black or dark gray;
• power is lost.

Noisy exhaust occurs more often on high revs. The reason is that the fuel does not burn completely, and therefore is removed along with the gases to the outside. However, a silencer stands in its way, which does not allow fuel to pass through, because it accumulates in it and explodes upon reaching a critical mass. As a result, there is a risk of destruction of the muffler or resonators.

Blackish smoke comes out due to the fact that the combustion of gasoline residues occurs in the exhaust system, where the products formed during ignition are not filtered.

The loss of power is due to the slow and incomplete combustion of the fuel. As a result, it literally floods the candles, which leads to the loss of a spark and, accordingly, to an even greater aggravation of the situation. The piston in this situation does not receive a normal push and a decrease in power occurs. Sometimes this indicator is restored for a while after driving the car at high speed, but usually the improvement is not observed for long.

Under such circumstances, the consumption of gasoline cannot but increase. The presence of a failure in the system does not prevent the flow of fuel into the engine, but it is used there with very low efficiency. A significant part of it is simply launched into the wind, and in the literal sense.

Other reasons

Quite often, the cause of the error in question is not gasoline, but air. The latter, in turn, may be given too little. Here you will need to check the performance of the air filter. It sometimes clogs and eventually ceases to perform its main function.

In the event that there are no complaints about the operation of this element, then the reasons may be the following:

• incorrect injector setting;
• breakdown of the DMRV;
• increased pressure in the fuel system;
• fuel getting into the lubricant.

In the first case, it is not uncommon for the injectors to open and close at the correct intervals, but each time the dose of gasoline is injected too much. It is almost impossible to check the serviceability of this element at home, so you will have to visit an auto repair shop. As a rule, the injectors that have become unusable are replaced with new ones.

Failure of the DMRV leads to the fact that on on-board computer incorrect data on air consumption are received, which forces the proportions to be changed in favor of increasing the proportion of fuel.

Modern cars drives It is characterized by a certain scheme of work. Inside the chamber of this system, the fuel-air mixture burns. This means that when refueling a car with gasoline or diesel, the driver provides only one necessary element for the movement of the vehicle.

The fuel is mixed with air. gasoline or diesel. The fuel evaporates in front of the valves. In the cylinders, the mixture of fuel and air is burned by an electric spark. If issued, this means that the system has detected a deviation. It's a rich mixture. But you can independently see the engine malfunctions caused by such a problem. How to fix it, every car owner should know.

General concept

Understanding what is too rich mixture (VAZ, Skoda, BMW, Chevrolet, etc.), a few words should be said about the fuel itself. It consists of gasoline (diesel) and air correlated in a certain proportion. Liquid fuel is supplied to the engine cylinders. This ratio largely depends on its quantity.

A rich mixture is one that contains more gasoline and less air. Since there is not enough oxygen inside the combustion chamber, the process of engine operation loses power. Afterburning of gasoline occurs because of this already in the muffler. Some auto mechanics call this state of the fuel high-calorie.

These violations are reflected on the outside. A characteristic black soot, soot appears on them. There may be several reasons for this state of the engine system. They must be found and eliminated.

When the mixture gets rich

Deviations in the preparation of the mixture appear as a result of certain failures of the vehicle's systems. The injector is responsible for the process of creating fuel. It prepares mixtures with a certain percentage of oxygen. It is this ability of the presented engine element that allows the engine to operate in different modes.

If necessary, the driver can, thanks to such a device, increase speed, cope with the rise, overtake, etc.

It is determined by a mathematical formula. The ratio of 14.7 kg of oxygen per 1 kg of liquid fuel is considered normal. If in this formula, for some reason, the amount of oxygen increases, such a composition is called poor. If the amount of fuel in the mixture rises, the mixture acquires the status of rich.

The owner of the car can independently adjust the level of oxygen supply to the fuel mixture. Mistakes made in this process lead to breakdowns and improper operation of the vehicle.

Signs of deviation

Rich mixture - VAZ, UAZ, BMW, Audi and other existing car brands - can be manifested by a wide range of deviations in the operation of the car. If such violations occur, it is urgent to find out the cause of this condition of the engine.

In vehicles in which an autoscanner is installed, when the deviations presented occur, an indicator lights up with the corresponding error code (P0172). The muffler in this case may emit loud pops. This is due to the combustion of air in the exhaust pipe. This is one of the first signs of violations.

In this case, you can notice the appearance of black, gray shades in the exhaust gases. This is also due to the inappropriate way the fuel burns out. Exhaust is not cleaned. The pipe contains a large amount of atmospheric oxygen. Therefore, the exhaust gas acquires a characteristic dirty tint.

Driving a car

Too rich mixture also appears in the management vehicle. Almost any driver will immediately notice this. The car becomes less dynamic. Engine power drops sharply. Since the combustion process in the motor chamber is slower, the mechanism is not able to work at full strength.

In some cases, the car may not even go. But this is with very serious deviations in the ratio of fuel and air in the combustion chamber.

When driving a car, the owner may notice that fuel consumption has increased. This is also a characteristic sign of engine malfunction due to rich mixture operation. This violation is explained simply. The engine in such conditions does not work efficiently. The fuel mixture is consumed incorrectly. To prevent a low combustion rate, the motor begins to inject more liquid fuel into the chamber.

Main reasons

There are several main reasons that cause deviations in the ratio of air and gasoline. The most basic of them can be deviations in the engine control system, as well as malfunctions of the air damper actuator. An injector malfunction can also explain why rich mixture. Carburetor if set incorrectly, it can also cause deviations. Another factor in the formation of a rich mixture is the clogging of the air filter.

Often the cause of violations in the fuel system is the wrong actions of the car owner. In order to reduce gas mileage or increase engine power, the driver may not properly adjust the system. As a result, he gets problems with the engine and the need for extraordinary maintenance or even repairs.

Fuel deviations

Since the process of forming a combustible mixture consists of two main components (gasoline and air), violations are possible from the supply side of each of them. Excess fuel is determined much less frequently than lack of air. But typical fuel supply violations should be considered in more detail.

Too rich mixture, the causes of which are related to fuel system, may be caused by high line pressure. This deviation is caused by a malfunction of the fuel pump or regulation system. To check this version, use a special fuel gauge.

Deviations in the composition of the mixture can be caused by the adsorber. Due to a malfunction in the vapor recovery system, a large amount of gasoline is admitted through it.

Also may be faulty when closed may be unable to hold fuel. This causes it to enter the chamber even when the nozzles are closed.

Air supply problems

"Rich mixture" error, which is determined by the vehicle diagnostic system, is much more often caused by insufficient oxygen supply to the combustion chamber. There are several reasons for this violation.

First of all, the air filter may be elementarily dirty. For some reason (difficult operating conditions, driving on dirty roads), this element of the oxygen purification system may become unusable even earlier than the period specified by the manufacturer. Therefore, it is necessary to visually evaluate the cleaner. If it is dirty, covered with oil, it must be replaced urgently. Otherwise, the motor will quickly fail.

In some cases, the cause of inadequate air supply to the combustion chamber may be a breakdown of its flow sensor. This will help to identify the system readings of the scanner. Sometimes a malfunction of the air pressure sensor in the manifold system is determined.

Automatic diagnostic system

If the vehicle diagnostic system indicates that a "Mixture too rich" error certain actions need to be taken. To do this, you need to understand the principles of the scanner.

Air is supplied to the fuel when diagnosing the MAP sensor and the lambda probe. Maybe it is caused by deviations of these particular systems. However, in addition to them, problems can be associated with deviations in thermal gaps (engine with LPG), with mechanical damage to sealing materials, insufficient compression or deviation during timing operation.

To understand why automatic diagnostics indicate such an error, the car owner can perform several actions. First of all, you need to analyze the information that the scanner provides. Next, you can artificially simulate the conditions for the appearance of such a malfunction.

The next step may be to check the components and mechanisms, such as contacts, the absence of suction, as well as the operability of systems associated with the supply of fuel and oxygen to the combustion chamber.

Troubleshooting a system error

If the diagnostic system indicates that the vehicle is using a rich mixture, a number of actions must be taken. A faulty node is found during a sequential check of each system. To do this, the JOT, MAF sensors, as well as the lambda probe, are checked with a multimeter.

If no deviations are found in these systems, it is necessary to pay attention to candles, coils and wires. Next, the fuel pressure is measured using a pressure gauge, and the ignition marks are also checked.

Then check the seals and connections at the air inlet, as well as the exhaust manifold. There shouldn't be any suction. After carrying out all the manipulations and eliminating the malfunction, the fuel supply adjustments are reset. In this case, long-term programs with respect to this setting return to their original value.

If in fuel tank getting ready mixture too rich, the first thing experienced auto mechanics recommend doing is resetting the advanced settings for the injector. If the owner made self settings fuel control system, he could make serious mistakes. A rich fuel mixture will lead to inevitable engine failure very soon.

If the cause of deviations is related to the nozzle system, this can be determined visually. With such a malfunction, traces of fuel combustion appear on the outside of the injector.

Burning and soot can also be found on one side of the sealing copper ring. Such deviations are caused by incorrect installation of the injector. If the O-ring is in the wrong place, similar malfunctions are also possible.

Rare breakdowns

Experts say that 90% of all errors are related to injector adjustment. Eliminating it is easy. The main thing is to pay attention in time to the incorrect operation of the car engine.

The most rare, exotic are considered to be malfunctions of the engine control unit, as well as the poor condition of the contacts. Sometimes there are cases of poisoning oxygen sensor. An experienced specialist is able to identify such deviations. In this case, not every car owner can solve the problem on their own.

Having considered what a rich mixture is, one can understand the danger of such a situation. In case of unforeseen situations, it is better to contact the service center. Service stations have essential tool which can be used to diagnose. This will save the car's engine.

Often, when the check engine lamp lights up, the diagnostics gives an error p0172. This means only one thing - too rich a mixture is being prepared in the engine of your car. Why is she rich? There may already be several answers here, let's try to figure out the main causes of a rich mixture.

So the problem arose out of the blue? The scanner showed an error, they say, the mixture is too rich, man. And the diagnostician took the money and said look further for yourself, I did the diagnostics

In addition to the scanner, you can also be told about the presence of an over-enriched mixture in the engine of your car when measuring CO and CH during the technical inspection. In general, it doesn’t matter where you learned that the engine has such a mixture, to troubleshoot you must understand what the very concept of this mixture means.

When there is too much gasoline and too little air in the fuel-air mixture, such a mixture is called rich.

The easiest thing to look for is in the fuel supply system (a lot of fuel), or in the air supply system to the combustion chamber (little air). Don't forget to start.

Causes related to the fuel system:

• Too much great pressure in the fuel line. And there may be a few more sub-points. Big pressure could be due to a faulty fuel pump. Or it could be a faulty fuel pressure regulator. There is a special fuel pressure gauge that checks the fuel pressure.
• The adsorber is not working properly. That is, the vapor recovery system is faulty. In this case, too much fuel may enter the intake through the adsorber, here you are cause of rich mixture.
• Injector failure. Tested on the bench for . That is, the injectors (nozzles) simply do not keep the fuel closed, and this is already a reason for it to get into the cylinders even with the nozzle closed.

Causes related to air supply:

• Clogged air filter. Trite? Yes. But this happens all the time, so check it out. Just keep in mind, if when checking the air filter you suddenly find that it is covered in oil, it means the engine is kirdyk ... almost.
• Same fault mass air flow sensor can cause a rich mixture. Or a manifold air pressure sensor. In any case, this is checked by, namely, by the voltage and air flow parameters or by the absolute pressure in the intake manifold.

On this main types of appearance rich mixtures run out and remain rare or exotic. Such as poor contact condition, error of the control unit itself