Among the various car breakdowns, you can find such a breakdown as misfires. If, when starting the car, the engine begins to shake strongly, and when idle speed stalls at all, this is a sign that there is a malfunction. This is especially noticeable when the engine is cold. Multiple misfires are dangerous for a car, as they cause undesirable consequences: increased fuel consumption, increased CO2 emissions, and high engine noise. All this causes unstable work car engine In this article I will talk about what causes misfire and how to repair them.

Misfire errors are indicated as follows:

• P0301 - misfire in cylinder 1;
• P0302 - in cylinder 2;
• P0303 - misfire in cylinder 3;
• P0304 - misfire in cylinder 4.

This is a phenomenon in a car engine when one of the cylinders gains speed more slowly than the others.

To understand where to start repairs, you need to understand the reasons that provoke multiple misfires.

So let's look at them:

• Causes of misfire in low-quality fuel. If you use fuel Low quality, then the injectors may become clogged. IN in this case the problem can be solved by changing gas station, or use high octane gasoline. Also, a pass may appear due to the slightest defects in the fuel pump;
• Due to broken or low-quality candles;
• Reasons – damaged high voltage wires or they have high resistance;
• Ignition and modules are faulty;
• Uneven compression is the source of the cause of abnormal air compression. fuel mixture;
• The causes of misfire may be hidden in the gas distribution mechanism. Multiple skips can occur as a result of incorrect timing adjustment or when it accidentally fails and wears out. The cause may also be leakage of hydraulic compensators;
• Failure of one of the cylinders.

By the way, misfires are very noticeable on a cold engine. This behavior of the car’s engine will not leave the driver indifferent.

Diagnostics and repair

Solve this problem the easier it is drivers whose car is “charged” with electric brains. At the station Maintenance Using a scanner, the car will show what the misfire error is. For example, misfire in cylinder 4 or misfire in cylinder 3. What can owners of domestic or inexpensive cars? That's right, step by step check on our own resorting, so to speak, to the “old-fashioned method”

To find the problem, you can start by doing the following:

1. Check wiring. High-voltage wires can often cause problems. It is necessary to carefully check the insulation, all connectors and the fixation of these connectors. The surface should be free of various types of chips and cracks. Also, bending the core is not allowed, which often happens with old wiring. If the problem is in the wiring, you will understand it immediately;
2. Candles. A thorough check of the spark plugs will help identify the problem if there is one. It is necessary to unscrew each candle and make visual diagnostics each. There should be no damage or blockages on them and the gap should be appropriate;
3. We inspect the distributor. To inspect it, you need to disassemble it. This part is a rather complex mechanism; for disassembly it is better to use a diagram. The diagram will help prevent any mistakes during reassembly and save your time;
4. Compensation in cylinders. You also need to check the compensation in the cylinders. To perform this procedure you will need some tools: a pressure gauge and a plug for the spark plug connector. IN seat this nozzle is inserted into the candles, and the pressure is checked using a pressure gauge;
5. Valves. By examining the valves, you can detect a malfunction. The fact is that valves can be of poor quality, so they are often the cause. You also need to check the level of adjustment. It is advisable to carry out inspection of the valve only after all the operations indicated above. Valves tend to get stuck when the car is subjected to strong mechanical shocks. Seals greatly affect compression as a result of their wear;
6. View cylinders. To check the cylinder you need to perform step-by-step checks. Turn on the ignition and set the idle speed. Next, start disconnecting the wires from the spark plugs one by one. If at the moment the cable is disconnected the operation of the motor changes, this means that this particular spark plug is damaged and needs to be replaced.

It is important to remember that this diagnostic and car repair involves contact with high voltage and hot parts. It is necessary not to forget about safety precautions and work extremely carefully. It is also important, when performing repairs, to follow the sequence indicated above. The sequence will help you identify the problem as quickly as possible.

Video “Causes of Misfire Errors”

The recording shows how to check the spark plugs.

One of the most unpleasant problems in engine operation internal combustion are misfires. This is the moment when one of all the cylinders does not work due to problems in the ignition system. There is an opinion that it is incredibly difficult to determine the causes of this problem, but misfires must be eliminated. When the fuel fails to ignite, one cylinder fails, which significantly affects engine power - 25% of the potential is lost power unit. The remaining three cylinders (if we are talking about four-cylinder engine) are forced to work for themselves and for that guy, so fuel consumption increases noticeably. In addition, a unit with a misfire starts poorly, trembles at idle and stalls under excessive loads. These are the unpleasant consequences of misfire.

It is worth noting that the ignition can be skipped either constantly or at certain intervals, or even chaotically. If a constant misfire occurs, one cylinder simply refuses to fire. If there is chaotic operation of the fuel ignition system, the cylinder may turn on and then skip its turn again. This causes very unpleasant fluctuations in speed, serious jerks when the cylinder is suddenly connected. The engine may also stall when the cylinder refuses to fire under load. It is imperative to deal with this problem and not let it take its course.

Constant misfire in one cylinder - studying and correcting the problem

It is worth considering three options for the causes of misfire in constant mode. The first option is a lack of spark, which can also be caused by a number of factors. The second feature of the problem is poor compression in the cylinder. This usually happens after executing repair work s or at the moment when the engine requires overhaul.

You can also consider a third option for the lack of fuel combustion - low quality of the fuel mixture itself. In this case, it is worth changing the gas station and knowingly taking good gasoline or diesel, fill the tank good fuel and drive a few kilometers. However, with bad fuel the engine may not start at all, but misfires are most often worth diagnosing from the following components:

• spark plugs - a faulty spark plug is the most common problem of poor fuel ignition;
• broken high-voltage wires can also become specific reason such an unpleasant problem with your car;
• problems in electronic control ignition or mechanical system(Hall Sensor);
• depressurization of one of the cylinders, decreased compression and lack of fuel ignition for this reason;
• too much wear on the cylinder due to uneven loads or simply too much wear on the engine;
• the ignition modules in each car have their own design and differ in many respects, they are also worth checking;
• it is necessary to adjust the ignition at the service in order to accurately understand that this factor does not cause a problem;
• sometimes the reasons may lie deeper and go into the diagnostic field of an exclusively professional service.

Despite the wide range possible problems, you can check almost all the popular factors for failure of the ignition system in your own garage. To do this, you do not need to use the services of a professional, unless you own an incredibly modern Japanese vehicle, in which it is not so easy to even open the hood yourself.

If the problem was not discovered on your own, you will have to contact service center and pay for professional diagnostics. In this case, you will be able to detect and fix the problem quickly enough, and also receive a guarantee from specialists that soon this situation will not happen again. True, the services are also different, and not every company will help you efficiently fix problems with your car.

Temporary or interval shutdown of the ignition on one cylinder

Problem permanent violation ignition failure is fraught with the fact that one cylinder from the general set in the car does not work. In this case, the engine shakes, this is very noticeable, power is lost and fuel consumption increases. But if the ignition failures are not permanent, but temporary, the problem may be perceived somewhat differently and interpreted by the service as a problem with another unit.

If while driving you feel periodic a sharp decline power and an inexplicable increase, most likely we are talking about a temporary shutdown of one of the cylinders. This possibility exists for all the reasons listed above, but not with the final failure of any unit, but with its initial breakdown. In this case, the symptoms of trouble with the car will be as follows:

• poor engine starting and operation of three cylinders on a cold car, connection of the fourth cylinder on a hot engine;
• temporary shutdown of one cylinder with a characteristic decrease in speed and loss of power;
• very high fuel consumption and deterioration motor oil due to the constant ingress of gasoline into it;
• decreased reliability of engine operation, the unit may stall without any particular reason in any conditions;
• a special manifestation of problems in the cold season or when high loads to the power unit;
• decreased traction and increased engine wear due to the need permanent job under load;
• fluctuation in speed Idling, serious jerks when moving smoothly in city mode.

As soon as such troubles happen to your car, you need to go to a service station and have the ignition system diagnosed. Temporary failure of one of the cylinders most often becomes a harbinger of large expenses for major renovation engine. That is why many owners prefer in this case to put the car in order as much as possible and sell the vehicle to another owner.

If you want to correct the situation and repair your car, be prepared for the unexpected high costs on the service. However, in reality worst case scenario You can purchase a complete engine from disassembly without spending too much money on this process. In this case, you will be able to update the potential of your car’s power unit and extend the life of the car for several more years. Engine operation during a misfire looks something like the following video:

Let's sum it up

Misfires can be either a harmless indicator of a failed spark plug or a serious demonstration of the need for professional intervention in the power unit system. By using professional diagnostics you can find out the source of the problem and get more information about how to solve this problem. Despite many difficulties in the process of finding an ignition problem, this problem can often be solved independently without any problems.

But if we are talking about increased wear power unit and poor compression in the engine, you will have to spend money on repairs by performing major restoration the most expensive component in your car. It is especially problematic to find and fix ignition problems in modern German or Japanese cars. These are machines that can accommodate Hi-tech and will actually become a difficult object to carry out repair work without special skills and special equipment. Have you ever tried to fix ignition problems yourself?

• How to check and identify non-functioning cylinders with your own hands?

I can assume that there is plenty of information on the Internet about the causes of misfires and life stories of cars with this disease.

For many car owners, it’s just a shock or even hysteria with an attack of panic, when the consumption is like that of a BELAZ, the traction is like that of an overloaded moped and you don’t know what, why and how, and whether it’s fatal or whether you can treat it yourself.

The logic is sometimes banal, but common cause of multiple misfires The problem is that there is no spark, which means there is no spark in the ignition system. Among the abnormal reasons may be the condition of the cylinder-piston group and the fuel supply, but these are more reasons why the engine is shaking or teasing.

In case of multiple and random misfires, the reason is in the ignition module, or less often in the engine wiring.

A dead spark plug or wire gives a consistent and logical misfire in the cylinder that is being powered, and not just any and whenever it wants, as happens with a dying ignition module.

If there is a misfire on all cylinders, the reason is similar, since the misfires can be sequential and this can be seen with computer diagnostics.

A clear example in the video of how the ignition system works and spark formation occurs.

Identify the causes of multiple misfires?

Candles

The condition of the spark plugs, a banal cause of misfires and an obvious way to find out, unscrewed it and looked. If the spark plug does not burn gasoline or gas, this can be clearly seen immediately after the engine has been running. Don't turn it too hot, but don't wait for the remaining fuel to evaporate.

High voltage wires

In general, everything is simple, we checked for rupture and resistance. Sometimes it’s not immediately noticeable, but if the wires have kinks or broken insulation, they can make themselves felt during vibration or humid weather.

Wiring

It may seem like a Herculean task, but if you know how to use a multimeter, it’s no more difficult than the first two causes of misfires. We take out the wires from the corrugated hoses and check for integrity one at a time. A broken wire may cause leaks during vibration when the engine is running.

Ignition coil

The cause of ignition coil failure is most often the failure of a spark plug or wires. Let's just say that the voltage in the coil is not released through the wire and spark into the spark plugs and takes the entire shock on itself.

Some engines have ignition coils arranged in such a way that after washing the engine they fail due to moisture ingress.

Ignition module

The most common reason for domestic cars due to poor quality ignition modules. The module conditionally consists of two parts; if there are gaps in two paired cylinders, and the wires lead to one side of the module, then the reason indicates itself.

It happens that the ignition module may be only half working. In this case, the thrust disappears and is not particularly noticeable in the operation of the engine, since it doubles synchronously.

How to check and identify non-functioning cylinders?

The surest and safest method, as well as the most correct and effective, is to connect to the computer of a good diagnostic program and an oscilloscope. This is best done by a diagnostic specialist.

The diagnostic program will show which cylinder is not working well. The elimination method described below is carried out using software shutdown nozzles, which is safe for the coil.

Engine performance graphs will show where there are dips in engine operation, at idle or under load.

Check the idle cylinders yourself

Identifying idle cylinders using spark plugs

1. We unscrew all the candles.
2. We arrange them in order, as in cylinders.
3. Let's look and compare the condition.

If we see that they are different, such as in the photo. The second and especially the fourth cylinder are slightly darker, which means that carbon deposits are created due to misfires in these cylinders.

We determine the performance of the cylinders using high-voltage wires

To identify problem cylinders, we use the method of eliminating working ones, or better yet, finding working cylinders.

Be careful and better not touch the body when you do the method described below, electricity, after all.

When the engine is running unevenly, one by one (carefully and for a short period) remove the wire from the spark plug. As soon as the engine’s performance has changed (it starts to stall, the speed has dropped, it starts to rev more strongly), we install the wire back on the spark plug, which means that this cylinder is working normally, i.e. it gives a spark. You can roughly assess the condition of the injectors.

When the wire is removed from the spark plug, and the engine operation has not changed, as it worked, it still works, unevenly and triples, or the changes are insignificant - this cylinder is problematic, since there is no spark in it or there are already gaps, a clear lack of spark and the wire in your hand confirms this .

Checking the ignition module yourself

Video: Dialing the wiring and ignition module

The best way to check the ignition module is to insert the wires into a working one and connect power to it, without installing it on the car. If you find a good seller and agree on this possibility, that will be good, but the chance that the new one is the same as your old one is available on cheap modules.

It is better to check on an ignition module that has been removed from a properly operating engine. You exclude checking with a defective coil, which drives you into a dead end.

Do you find it difficult to get uphill only in second gear? In this case, you may suspect a misfire. And if available, you can detect the “P” error. In this case, the numbers next to the letter will indicate which cylinder there are misfires: 0301 - in the first, 0302 - in the second, 0303 - in the third, 0304 - in the fourth. What is the problem?

Misfire is a phenomenon that occurs in an engine when one cylinder accelerates slower than the others, thereby disrupting the operating cycle. As a result, the exhaust deteriorates and the car “jerks” rather than drives.

In this case, there are two ways: visit a car service center, where qualified specialists will solve your problem, or try to fix the misfire on your own. The causes of the problem can be very different. In this article we will look at only the most common ones:

1. Due to poor fuel quality, the injectors become clogged. In this case, you only need to replace gas station or switch to high-octave gasoline. But it is worth knowing what can occur due to some breakdowns of the pressure regulator, fuel pump or due to a clogged filter.

2. Perhaps your spark plugs are broken - with a large or small gap. They may also simply be of poor quality.

If you don't have electronic assistant, then you can find the reason using old time-tested methods. Start with the electrical equipment under the hood: spark plugs, high-voltage wires, condition of the fuel pump, measuring compression in the cylinders. At the final stage, if misfires are not eliminated, proceed to inspect the engine. Remove cylinder head cover and diagnose the condition of the valve guides and rings.

For some internal combustion engine models, the camshaft is located in the cylinder head. In this case, in order to inspect the valve springs, it is necessary to remove the cylinder head. Good luck finding the cause!

What kind of service is this?

Unfortunately, misfire is pretty popular problem among drivers, which can have various causes. First of all, it is necessary to clearly understand what exactly such a defect is. Misfire is a malfunction in the engine, which manifests itself in the fact that one of the cylinders accelerates more slowly than the others, thereby disrupting the normal rhythm of the internal combustion engine. Such a defect leads to the development of various problems and unpleasant consequences, such as deterioration of emissions and a significant increase in fuel consumption. However, most important consequence A misfire is when the car becomes difficult to drive. Therefore, when similar problem it needs to be fixed urgently, because it can lead to serious damage to the car. - also a good reason to call a specialist.

What happens during a misfire?

If you notice that the car has lost its former strength and speed, cannot provide normal driving, the car constantly jerks and stops - it’s time to contact a professional for diagnostics. As a rule, the main manifestations of a car misfire are:

• loss of engine power;
• interruptions in engine operation;
• problems with going up the mountain;
• Jerky driving, multiple stops.

The occurrence of such situations is a sign of misfire. Such ignition defects can occur spontaneously and also disappear spontaneously. Wherein Misfire can occur even at idle. However, what to do if your car suffers from multiple misfires? Misfire is, first of all, a malfunction in the engine, because such a defect often manifests itself due to malfunction or failure of one of the cylinders. Therefore, eliminating the ignition problem should begin with a detailed diagnosis of the engine’s working cylinders.

Causes of misfire

U professional drivers and amateur motorists often have problems with ignition: The brake pedal doesn't press well or is pushed to the maximum, the car “jerks”, the car makes strange sounds, but does not move normally, and the problem “code P000 cylinder failure” appears on the on-board computer. If you have modern model car with built-in on-board computer, finding a faulty part that causes ignition problems is not difficult. You just need to use a car tester, which will help you quickly diagnose the condition of your car. However, if you own a car old model without a built-in computer, the cause of the breakdown must be found manually.

Multiple omissions ignition may have various reasons. To quickly and competently eliminate this problem, it is necessary to carry out comprehensive diagnostics car, which will help identify breakdowns that caused cause of misfire.

When conducting self-diagnosis If there is a car malfunction, it is recommended to pay attention to the following parts of the operating mechanism:

• spark plugs - the reason may be hidden in low-quality parts, punctured or spark plugs with a small gap;
• fuel-air mixture– when buying a low-quality mixture, the nozzles may become clogged and deteriorate fuel pump, the filter becomes clogged, which becomes cause of misfire;
• high-voltage wires - the slightest damage, deviations or high resistance can cause not only a misfire, but also serious damage to the car;
• gas distribution mechanism - incorrect installation, adjusting the mechanism gaps is the most common cause of ignition problems;
• engine cylinders - a malfunction of one of the internal combustion cylinders, a decrease in the gap between the cylinder and the piston leads to a malfunction of the ignition system.

Eliminating misfire in a cylinder

If there is a defect in the cylinder, misfire at idle can become a real death sentence, because without paying due attention and not eliminating the problem in time, it will immediately lead to engine damage.

Only a complete and detailed diagnosis will help identify malfunctions in the operation of a specific cylinder. To carry out such diagnostics, the mechanic uses a special device called an autoscanner. This device allows you to quickly and accurately find a defect in the operation of the cylinder, effectively eliminate the problem and prevent its occurrence in the future. Self-diagnosis is not recommended. Even with the help of this device, with insufficient competence, you can never be completely sure of the correctness of the “diagnosis”.

Keep in mind

If your car is equipped with an on-board computer, it will be able to give valuable recommendations regarding the cause of misfire. You need to pay attention to the error code shown on the screen:

• P020X - a code like this indicates a problem with the fuel injectors;
• P030X - a similar code indicates a problem with the cylinder, the last digit of the code indicates the number of the defective cylinder;
• P0300 - a code like this indicates a problem with the spark plugs; to fix it, you just need to replace the defective spark plug;
• P040X - a code like this indicates a problem with the exhaust system.

If problems arise with the spark plugs, you can fix such a defect yourself. If there are problems with other engine parts, the intervention of a professional mechanic is necessary. do-it-yourself repair can lead to serious damage auto.

Misfire squeak from brake mechanisms- also a good reason to conduct a diagnosis.

Signs that indicate you need this service

• Spark plugs or high-voltage wires are faulty
• Ignition coil malfunction
• Piston rings broken
• Valves burnt out or bent
• Broken valve springs
• Camshaft worn out
• Fuel burner does not work