Too rich mixture: causes and solutions from professionals

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

Modern cars are powered by an internal combustion engine (ICE). 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.

Fuel is mixed with air. The nozzles spray petrol 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 the car scanner generated an error p0172, this means that the system has determined a deviation. It's a rich mixture. But you can independently see the engine malfunctions caused by such a problem. Every car owner should know how to fix it.

General concept

Digging into the concept of what is too rich a 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. From its quantitythis ratio depends a lot.

Rich is a mixture in which there is more gasoline and less air than normal. 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 refer to this state of fuel as high-calorie.

These violations are reflected in the appearance of spark plugs. 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 work in different modes.

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

Rich mixture on the injector 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 becomes rich.

The car owner can independentlyadjust the level of oxygen supply to the fuel mixture. Mistakes made in this process result in vehicle breakdowns and malfunctions.

Signs of deviation

A rich mixture - VAZ, UAZ, BMW, Audi and other existing car brands - can manifest itself in a wide range of deviations in the car. If such violations occur, it is urgent to find out the cause of this engine condition.

In vehicles equipped with an autoscanner, when the above deviations occur, the 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

Too rich mixture also appears when driving. 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 speed.

In some cases, the car may not even go. But this is atvery 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 become higher. 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 low combustion rate, the engine starts 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 a rich mixture is detected. The carburetor, if set incorrectly, 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. Excessfuel is determined much less frequently than lack of air. But typical fuel supply problems should be considered in more detail.

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

The injectors may also be faulty. A closed injector may not be able to hold fuel. This causes it to enter the chamber even when the nozzles are closed.

Air supply problems

The "Rich Mix" error that the vehicle's diagnostic system detects is much more likely to be caused by insufficient oxygen supply to the combustion chamber. There are several reasons for this violation.

First of all, the air filter may be simply 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 sensorconsumption. 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's diagnostic system indicates that a mixture too rich error has occurred, certain actions must 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 the error P0172 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.

To understand why automatic diagnostics indicate such an error, the owner of the car can perform several actions. First of all, you need to analyze the information that the scanner provides. Then 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, lack of suction, as well as the operability of systems associated with the supply of fuel and oxygen to the combustion chamber.

Fixing 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 in these deviation systemsnot detected, you need to pay attention to the 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 on 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. At the same time, long-term programs with respect to this setting return to their original value.

Expert Tips

If the mixture in the fuel tank is too rich, the first thing experienced auto mechanics recommend doing is to reset the advanced settings for the injector. If the owner made independent adjustments to the 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 injector system, this can be determined visually. With such a malfunction, traces of fuel combustion appear on the outside of the injector.

Cinder 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 problems are also possible.

Rare breakdowns

Experts say that 90% of all "Rich Mix" errors are due to injector adjustment. Eliminating it is easy. The main thing is to pay attention to incorrect work in time.car engine.

The most rare, exotic are the malfunctions of the engine control unit, as well as the poor condition of the contacts. Sometimes there are cases of oxygen sensor poisoning. 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 points have the necessary tools with which you can diagnose. This will save the car's engine.