Modern cars are driven 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 filling the car with gasoline or diesel, the driver provides only one necessary element for the movement of the vehicle.
Fuel mixes with air. Nozzles spray gasoline or diesel. Fuel evaporates in front of the valves. In cylinders, a mixture of fuel and air burns out from an electric spark. If the car scanner generated error p0172, this means that the system detected a deviation. This is a rich mixture . But you can independently see engine disruptions caused by such a problem. How to fix it, every car owner should know.
General concept
Delving 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. This ratio largely depends on its quantity.
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 engine operation process loses power. The burning out of gasoline is due to this already in the muffler. Some auto mechanics call this state of fuel high-calorie.
These violations are reflected in the appearance of the spark plugs. A characteristic black soot, soot appears on them. There can be several reasons for this condition of the engine system. They must be found and eliminated.
When the mixture gets rich
Deviations in the preparation of the mixture result from certain malfunctions of the vehicle systems. The injector is responsible for the process of creating fuel. He makes mixtures with a certain percentage of oxygen. It is this ability of the presented engine element that enables the engine to work in different modes.
If necessary, the driver can, thanks to such a device, increase speed, cope with the rise, go on overtaking, etc.
The rich mixture on the injector is determined by the mathematical formula. A ratio of 1.7 kg of liquid fuel to 14.7 kg of oxygen is considered normal. If in this formula, for some reason, the amount of oxygen increases, this composition is called poor. If in the mixture the fuel quantity indicator rises, the mixture becomes rich.
The car owner can independently adjust the level of oxygen supply to the fuel mixture. Errors made in this process lead to breakdowns and improper operation of the vehicle.
Signs of rejection
A rich mixture of VAZ , UAZ, BMW, Audi and other existing car brands can manifest itself with a wide range of deviations in the operation of the car. If such violations occur, it is urgent to find out the reason for this condition of the engine.
In vehicles in which an autoscanner is installed, when the indicated deviations occur, the indicator lights up with the corresponding error code (P0172). In this case, the muffler can make loud pops. This is due to the burning of air in the exhaust pipe. This is one of the first signs of disruption.
In this case, you can notice the appearance in the exhaust gases of black, gray shades. It is also associated with an inappropriate method of burning out fuel. The exhaust does not go through any cleaning. The pipe contains a large amount of atmospheric oxygen. Therefore, the exhaust gas acquires a characteristic dirty hue.
Driving a car
Too rich a mixture also appears when driving. Almost any driver will immediately notice it. The car is becoming 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 become greater. This is also a characteristic sign of engine malfunction due to operation with a rich mixture. This violation is explained simply. The engine in such conditions is inefficient. The fuel mixture is not consumed correctly. To prevent a low combustion rate, the engine begins to inject more liquid fuel into the chamber.
Main reasons
There are several main reasons that cause deviations in the ratio of air to gasoline. The most basic of these may be deviations in the engine control system, as well as disruptions in the operation of the air damper drive. Injector failure can also explain why a rich mixture is determined . If set incorrectly, the carburetor can also cause abnormalities. 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 incorrectly adjust the system. As a result, he gets problems with the engine and the need for extraordinary maintenance or even repairs.
Fuel deviation
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 often than lack of air. But typical fuel supply disruptions should be considered in more detail.
Too rich a mixture, the reasons for which are associated with 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 pressure gauge for fuel.
Deviations in the composition of the mixture can cause an adsorber. A large amount of gasoline is let in through it due to a malfunction in the vapor recovery system.
Injectors may also be faulty . The injector in the closed state may not be able to hold the fuel. This causes it to enter the chamber even with the nozzles closed.
Air Supply Malfunctions
The “Rich mixture” error , which is determined by the vehicle’s 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 can 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 time 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 an inferior air supply to the combustion chamber may be a failure of its flow sensor. This will help to identify the scanner reading system. Sometimes a malfunction of the air pressure sensor in the collector system is determined.
Auto Diagnostic System
If the vehicle’s diagnostic system indicates that a “Too rich mixture” 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 during the diagnosis of the MAP sensor and 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 gas turbine), mechanical damage to sealing materials, insufficient compression or deviation during operation of the timing.
To understand why automatic diagnostics indicate such an error, the car owner can take several actions. First of all, you need to analyze the information that the scanner provides. Further, it is possible to artificially simulate the conditions for the appearance of such a malfunction.
The next step may be to check the nodes and mechanisms, such as contacts, lack of suction, as well as the performance of systems associated with the supply of fuel and oxygen to the combustion chamber.
Resolving a system error
If the diagnostic system indicates that a rich mixture is being used by the car, a number of actions must be performed. A faulty node is found during a sequential check of each system. For this, the JOT, MAF sensors, as well as the lambda probe, are checked with a multimeter.
If deviations are not found in these systems, it is necessary to pay attention to candles, coils and wires. Next, the fuel pressure is measured using a manometer, and the ignition marks are checked.
Then check the seals and connections at the air inlet, as well as the exhaust manifold. There should not be a choke. After all the manipulations and troubleshooting, the fuel feed adjustments are reset. In this case, long-term programs regarding this setting are returned to their original value.
Expert Advice
If a too rich mixture is prepared in the fuel tank, the first thing that experienced auto mechanics recommend doing is to reset the additional 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 an inevitable engine breakdown very soon.
If the cause of the deviation 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.
Cinder and soot can also be found on one side of the copper sealing ring. Such deviations are caused by improper installation of the injector. If the o-ring is not in place, similar malfunctions are possible.
Rare breakdowns
Experts say that 90% of all Rich Mix errors are related to adjusting the injector. It is not difficult to eliminate it. The main thing is to pay attention to the incorrect operation of the car engine in time.
The most rare, exotic are considered to be malfunctions of the engine control unit, as well as poor condition of the contacts. Sometimes there are cases of poisoning of the oxygen sensor. Identify such deviations is capable of an experienced specialist. In this case, not every car owner can independently solve the problem.
Having considered what a rich mixture is, you can understand the danger of such a situation. If unforeseen situations arise, it is better to contact a service center. At service points there is a necessary tool with which you can perform diagnostics. This will save the car engine.