Multiple misfires in Priora

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Error code P0300 indicates a violation of the ignition order , which stands for random multiple misfires of the cylinders ; in English, the diagnostic tool displays: “Random cylinder misfire detection system.” If a misfire is detected in a specific cylinder, then the last digit “P030x” will change to 1, 2, 3, 4 and so on up to 6 or even 12, depending on which particular “pot” the misfire is in. So error P0300 is derived from errors such as P0301, P0302, P0303, P0304. Most often they occur due to a lack of spark, a fuel supply failure or problems with the exhaust gases.

Let's look at the list of possible causes of misfires, why error p0301, error p0302, error p0303, error p0304 or others of this kind appears, the consequences and methods of elimination, in more detail.

Symptoms of malfunction

The main driver symptom of a P0300 is the MIL (malfunction indicator light) illumination. It is also called Check engine or simply “check light”.

They can also appear as:

The “Check engine” warning light on the control panel will light up (the code will be stored in the ECM memory as a malfunction).
The engine stalls or has trouble starting.
Floating speed, as well as attempts to stall at idle.
Jerking/misfire at idle or under load.
Poor speed gain.
Increased fuel consumption.
Reduced engine power.
Smell of fuel from the exhaust.

This malfunction is considered serious and must be corrected as soon as possible. Because prolonged driving with a misfire can cause costly damage to the engine and catalytic converters.

A misfire means the fuel is not being processed in the combustion chamber. This can happen for a variety of reasons. To determine the root of the problem, all options must be tested. Starting from the simplest to deeper problems. The search should be done in the following order:

They usually start with the spark plugs. This is the most common cause of cylinder failure. First you need to inspect the candle visually. In working condition, it should be light sand color. If the spark plug is black or gray, you need to clean it. To do this, it is annealed over fire and cleaned with fine sandpaper. Another equally common cause of spark plug failure is a broken gap. It can be both large and small. To eliminate the malfunction, the electrode is pressed out or, on the contrary, pressed, adjusting the gap. After all the steps, you should check the operation of the candle. The spark it creates should be white and blue. This is described in detail in the article “What should be the gap on the spark plugs”;

Faulty injectors. Engine trouble often occurs due to problems with the condition of the injectors. Usually this malfunction is shown by computer diagnostics. The cause is often poor quality fuel. It clogs the injectors and they stop functioning normally. This can be treated by flushing the power system; in extreme cases, you will have to replace the faulty part. This problem can occur on both gasoline and diesel units;
Low compression. This is checked by measuring this indicator. If it is less than 11 points, then measures should be taken to repair the engine;
Incorrect timing adjustment. This usually occurs due to wear of drive parts. Sometimes the reason is a failure in the settings of the hydraulic valve compensators;
Air entering the fuel system. This could be damage to the intake manifold or a change in the condition of the injector rings. Most often, this problem is accompanied by misfires in different cylinders. You should find the cause and remove it.

How to detect a malfunction yourself

We also recommend reading our expert’s article, in which he talks in detail about what a contactless ignition system is.

Be sure to read our specialist’s article, which tells you how to set the ignition correctly.

In cars with ECU

In cars with an ECU, troubleshooting is a fairly easy task. To do this, you need to connect an autotester and find the error code. If among the error codes there is an indication of a specific cylinder, then you should pay special attention to the condition of the element. Perhaps the problem is hidden in the armor wires or spark plugs that go to this cylinder. The gaskets may also need to be replaced. If a complex error (p0300) is issued, then you should pay special attention to the quality of the fuel and the filter.

Even domestic cars now have electronic units installed. If the car initially has an ECU, but its performance leaves much to be desired, then you can replace the part at a certified service station. The new “brains” must be compatible with the previous model. Thanks to the new electronic control units, you can easily find misfires in the 1st and 4th cylinders of the VAZ-2114 or on any old foreign car, as well as diagnose the operation of the 2nd and 3rd cylinders without unnecessary hassle.

Possible solutions

If there are no symptoms, the easiest thing to do is reset the code and see if it comes back.

If there are symptoms such as the engine stumbling or hesitating, check all wiring and connectors leading to the cylinders (such as spark plugs). Depending on how long the ignition system components have been in the vehicle, it may be a good idea to replace them as part of your regular maintenance schedule. I would recommend spark plugs, spark plug wires, distributor cap and rotor (if applicable). If not, check the coils (also known as coil packs). In some cases, the catalytic converter has failed. If you smell rotten eggs in your exhaust, your cat's converter needs to be replaced. I have also heard that in other cases the problem was faulty fuel injectors.

What can multiple misfires lead to?

Single misfires are only a signal to the owner of a VAZ 2114 about problems with the engine.

Numerous incidents entail the following consequences:

As a result of misfires, unburnt fuel will enter the catalytic reduction system. Because of this, the converter will overheat and fail.
With repeated misfires, some of the gasoline will enter the lubrication system through the walls of the idle cylinder. Oil diluted with gasoline will lose its properties and will not be able to provide high-quality lubrication of loaded engine elements.
All these factors can lead to engine failure and the need for expensive repairs.

Technical description and interpretation of error P0303

The OBD II error code P0303 is a generic one that reads “Cylinder #3 misfire detected.” Set when the PCM (powertrain control module) detects a misfire in the third cylinder.

The misfire detection system uses input data that is sent to the PCM through dedicated feedback circuits. If the PCM does not receive feedback, it interprets this as a misfire.

Trouble code P0303 indicates that the third cylinder is misfiring. They occur when insufficient fuel is burned in the cylinder. Efficient combustion of fuel is important. Because fuel combustion is the source of energy for engine operation.

Misfires can be caused by many reasons. Due to a faulty ignition system, fuel system or internal engine failure. Often the fault occurs due to worn spark plugs, spark plug wires or a faulty coil.

Diagnostics

Error on display - misfire

An unpleasant situation when a motorist comes to the car, starts it, but cannot move off normally because it begins to twitch. This means that there are problems with the ignition.

Diagnosing a malfunction is quite easy, because the electronic engine control unit immediately recognizes the error.

Before you get into the ECU, you should look to see if the “ Check Engine ” light has come on on the instrument panel. So, this is a signal that errors have appeared in the operation of the main power unit. If the “brains” controller is equipped with a display located on the instrument panel, then the error can be determined immediately.

It will be classified as P0300. Since the car has 4 cylinders, each will have its own meaning. So, let's look at the error codes associated with misfires:

P0301 – first cylinder.

P0302 – second cylinder.

P0303 – third cylinder.

P0304 – fourth cylinder.

The ECU will indicate its own error for each cylinder

But, if the display is not on the dashboard, then you need to connect to the ECU to identify these codes.

Causes of the problem

Now that the diagnosis has been carried out, you can proceed directly to considering the causes of the problems. The Samara-2 engine is no different from the rest of the Lada family of engines, and therefore the reasons for misfire will be the same for everyone. So, let's look at where to look for the problem:

Spark plug.
Wiring.
Ignition coil.
Injectors.
Compression.
Gas distribution mechanism.
Air in the fuel system.
Clearances between cylinder and piston.

As you can see, there are enough reasons, so you will have to work hard to eliminate them.

Misfire indicator 4 cylinders

Methods for eliminating misfires

The causes of the malfunction have been identified. They are based on a violation of the air-fuel mixture, as well as malfunctions in the ignition. It is with the second reason that you should start looking for where the problem is hidden.

Spark plug

Soot and oiliness of candles

Repeatedly, the poor condition of the spark plugs has caused unstable engine operation.

Thus, the presence of carbon deposits or oiliness of the element can lead to misfires. Another factor that will affect the operation of these parts is an incorrectly adjusted gap or a crack in the spark plug body.

You can diagnose candles quite easily . To do this, you need to unscrew them and visually inspect them for plaque, cracks or other damage. Also, using a tester you need to check the resistance. Next, using a spark plug tester or the old “old-fashioned” method, determine whether there is a spark.

You can determine the condition of candles by color

If at least one of the above faults is present, then it is necessary to replace the broken spark plug. Many motorists recommend changing the entire set, having previously adjusted the gaps and cleaned the spark plug channels from dirt and oil.

Wiring

Breakdown of high-voltage wires

In some cases, the cause of a vehicle misfire may be the wiring. Thus, breakage or breakdowns of high-voltage wires, as well as wiring elements, will become a problem in which power will not reach the spark plugs, and, accordingly, there will be no spark.

Eliminating the problem is to replace the high-voltage wires, as well as look at the wiring associated with the ignition.

Ignition coil

Measuring work on the ignition coil using a tester

Another cause of misfire could be the module or coil. In this case, it is necessary to carry out diagnostics, as well as repair or replace the failed element.

Injectors

The process of diagnosing the condition of injectors

Malfunction of the ignition may be due to an incorrect fuel mixture ratio, which will be caused by improper operation of the injectors. Since the quality of the fuel mixture leaves much to be desired, the fuel spray nozzles become clogged quite often. This is why they can cause a misfire effect.

Thus, to eliminate the malfunction, it is necessary to periodically diagnose and clean the unit. If this does not help, then it is necessary to replace the damaged elements.

Compression

Compression measurement in cylinders

A drop in compression in the engine cylinders can also cause multiple misfires to occur. In this case, compression will not occur completely, and the fuel will not be completely burned, which can affect the operation of the spark plugs, which are responsible for igniting the fuel mixture.

To eliminate this malfunction, you will have to dismantle the engine and find the cause during disassembly . As practice shows, this will be a major overhaul of the main power unit. This occurs in high mileage vehicles.

Gas distribution mechanism

Timing belt setting process

An incorrectly aligned gas distribution mechanism can cause multiple misfires. Thus, the operation of the engine cylinders will be disrupted, which will result in incomplete combustion of the fuel mixture. To eliminate the malfunction, it is necessary to set the timing belt according to its marks.

It is also recommended to check the belt for stretching and diagnose its condition, because this may be the reason.

Communities › Lada Granta › Forum › Errors P0363 and P1304

Hi all. Today I tuned up the engine and the BC showed the following errors: P0363 - Misfires detected, fuel supply to idle cylinders is turned off. P1304 - misfire detected, critical for the converter in cylinder 4. This has already happened (tripleting), but there was no bk and I don’t know the codes. Then I changed the spark plugs and everything went away. Now replacing the spark plugs did not help. Who can help with advice? I don’t want to go straight to the service center, I hope I can fix it myself.

Maybe a coil then?

I've read a lot about this problem. Maybe I/O wires, maybe a coil. maybe something wrong with the injectors. Or do the valves need to be adjusted?

Well, I don’t know then, if you change everything at random, it will probably be a little expensive?! or try removing it from the donor)

I'll check the wires tomorrow. if they are ok, I’ll go for diagnostics

it is truth too! write back later, interesting.

I also had triplets, also 8-grade, there was no BC, I took it to the nearest service center for diagnostics. 15 minutes and the verdict - ignition coil Price: 700 rubles + 200 for diagnostics

There was a letter about low-quality coils and their replacement under warranty. In April, one of mine burned out - they replaced it under warranty. Two weeks ago, during scheduled maintenance, everything was changed. The letter itself with the list of cars is here on the forum. www.drive2.ru/c/1082768/

you have 16 valves, and the vehicle has an 8-valve 87 mares, a different engine, a different ignition coil

Why did the spark plugs require replacement the first time? Maybe gasoline with additives and red spark plugs? Are the candles brick white now? Red ones are additives to gasoline based on metal oxides - they create conditions for breakdown of the insulator.

The problem with the injectors should give itself away while driving - it won’t drive normally. BB wires, if they do not touch metal, are also unlikely to be sewn somewhere.

There may also be poor pressure in the fuel rail, and due to the heat (closeness of the exhaust to the intake), there may be vapor locks in gasoline when the pressure decreases - as an option. Under load, gasoline is consumed faster and cools itself. If the BC is multitronics, then you can look at the injection time graph to see if there are any sudden jumps in fuel supply time.

And it’s not entirely clear whether this problem doesn’t go away? I also encountered misfires at home (the multitronics BC showed an error, on the shuttle BC one-time misfires are not yet displayed). I didn’t even understand whether the engine was damaged or not, because... The error occurred 3 times in 2 months at xx after starting the engine.

My spark plugs had a reddish coating, then I immediately changed the gas station, but still didn’t change the spark plugs.

I changed the spark plugs for the first time for prevention. I installed some French ones. There were 3 times when the check light came on, the car stalled and stopped driving. The officials shrugged their shoulders. Then I realized that it was the candles (it was just that during the next “attack” I put in new candles and everything went away), but now it didn’t help. but here’s the thing: in the morning, two days ago, I swapped the wires of the second and fourth cylinders (both on the spark plugs and on the ignition module) and the error changed to 1301 (it was 1304). but I never understood why. In the end, after about 20 minutes the car started moving, I cleared the errors and everything was okay. It seems that only diagnostics will reveal the problem

On which cars is this problem most common?

The problem with code P0303 can occur on different machines, but there are always statistics on which brands this error occurs more often. Here is a list of some of them:

Audi (Audi a4, Audi a6)
BMW (BMW E46)
Chery (Chery Tiggo)
Chevrolet (Chevrolet Aveo, Cruz, Orlando, Trailblazer)
Chrysler (Chrysler Voyager, PT Cruiser)
Dacia (Dacia Largus)
Daewoo (Daewoo Gentra, Nexia)
Dodge (Dodge Caravan, Stratus)
Fiat
Ford (Ford Windstar, Mondeo, Fiesta, Figo, Focus, Fusion)
Honda (Honda Accord, Civic)
Hyundai (Hyundai Accent, Getz, Santa Fe, Solaris, Tucson, Elantra)
Infiniti
Jeep (Jeep Grand Cherokee, Liberty)
Kia (Kia Rio, Sid, Sportage)
Lexus (Lexus rx300)
Mazda (Mazda 3, Mazda 6, Mazda cx7, Tribute, MPV)
Mercedes
Mitsubishi (Mitsubishi Galant, Lancer, Space Star, L200)
Nissan (Nissan Almera, Qashqai, Terrano)
Opel (Opel Astra, Vectra, Zafira, Corsa, Meriva)
Peugeot (Peugeot 307, 308)
Renault (Renault Duster, Logan, Sandero)
Skoda (Skoda Yeti, Octavia, Fabia)
Ssangyong
Subaru (Subaru Outback, Forester)
Suzuki (Suzuki Grand Vitara)
Toyota (Toyota Camry, Corolla, Prius, Fielder)
Volkswagen (Volkswagen Golf, Jetta, Caddy, Passat, Polo Sedan, Touareg, Tiguan)
Volvo
VAZ 2110, 2112, 2114, 2115
Volga Cyber
Gazelle Business
Lada Kalina, Largus, Niva, Priora
UAZ Patriot

With fault code P0303, you can sometimes encounter other errors. The most common ones are: P0016, P0102, P0113, P0171, P0174, P0183, P0203, P0267, P0300, P0301, P0302, P0304, P0305, P0306, P0316, P0363, P0400, P0420, P1303.

Source

Causes of multiple misfires

There is no spark or the strength of the spark discharge is insufficient to ignite the fuel injection pump. The cause of interruptions in the operation of the ignition system may be spark plugs, high-voltage wires, a coil, or an ignition module.
Loss of engine compression. Burnout of valves, breakdown of the cylinder head gasket are the most likely causes. Even wear of hydraulic compensators, incorrect valve clearance, or failure of timing marks can lead to a similar problem.
Malfunction of the injector or its control circuit. If the injector hangs open, the control wire has a short to ground, and the fuel injection pump will be over-enriched. The fuel mixture will not burn due to either excessive leanness or an over-rich mixture. Therefore, if there are multiple misfires, the fuel pump should not be excluded from the list of causes.
Suction of unaccounted air. For example, in the place of the gasket between the intake manifold and the cylinder head. In an unheated state, the gap at the depressurization site increases, so more unaccounted air enters the cylinders. Misfires occur due to excessive leanness of the mixture. Among the list of reasons, one should not exclude leaking injector O-rings and cracked vacuum system hoses.

Signs of misfire: the engine throttles, power decreases, fuel consumption increases. Uneven operation is clearly noticeable on 3, 4, 5-cylinder engines, but on V-shaped 6 and 8-cylinder internal combustion engines, it is more difficult to notice the shutdown of one of the cylinders.

Error codes

Self-diagnosis of a modern injection system is capable of recording misfires and determining which cylinder is the cause of uneven engine operation. Therefore, we recommend starting with diagnosing the current fault codes. When searching for the cause of a breakdown, it is important to understand in which particular engine operating mode the misfire error occurs.

Without ignition, there is no power stroke in the cylinder, which affects the crankshaft rotation speed. The engine ECU receives information from the crankshaft position sensor, so based on the moment of deceleration, the CV can calculate which cylinder is misfiring.

P0300 – multiple misfires. This means that burning problems are not limited to just one cylinder;
P03001, P03002, P03003, P03004, P0300n... - misfires in a specific cylinder. Where N is the serial number of the combustion chamber in which the malfunction occurs.

You can determine error codes by connecting to the OBD II connector using a simple diagnostic tool like ELM 327. It is important that the software version allows you to connect to the engine control unit on your car model.

How to identify a cylinder

If the engine is misfiring, but you do not know which cylinder is causing the problem, with the engine running, remove the high-voltage wires one by one or disconnect the connectors of the ignition modules and fuel injectors. The shutdown of the working cylinders will be noticeable by a drop in speed. The problems will be in that “pot” that does not react in any way to disconnecting the GDP/connector. We have identified the inoperative cylinder, so we move on to finding the cause of the misfire.

Ignition system diagnostics

We will not consider diagnostics of the secondary ignition circuit, which requires an oscilloscope and basic skills in working with sensor signals. Let's look at the basic verification methods that you can do yourself.

Remove the spark plug. Measure the air gap, assess the condition of the electrodes, insulator and the amount of carbon deposits. We described the diagnostic process in more detail in the article “Symptoms of faulty spark plugs.”

If the spark plug is wet and there is a strong smell of gasoline, it means that fuel is being supplied to the cylinder and the power system should be the last thing to complain about.

The best way to independently determine the cause of a misfire in a cylinder is to first swap the spark plugs, then the GDP and ignition modules. Before starting after changing elements, erase all error codes. You can determine a non-working “boiler” by reading current errors or using the method described above.

Screw the spark plug from the cylinder that has ignition problems into a working “pot”. If the problem moves to a previously good cylinder, then the cause of the misfire is in the spark plug. Do the same with GDP and individual ignition coils.

On cars with a DIS system, the design of which involves one coil for 2 cylinders, a malfunction of the ignition coil will manifest itself as misfire in 2 “boilers” at once.

Checking high voltage wires

Measure GDP resistance. If you know how to use a multimeter, you can test the high-voltage wires yourself and compare the values obtained with the nominal values. Infinite resistance indicates a break - such a high-voltage wire should be replaced.

Definition of breakdown. Spray the GDP with water, start the engine. Connect one control contact to an unpainted metal part in contact with the body. Run the second contact along each wire. There should be no spark breakdown between serviceable high-voltage wires and the control panel.

Attention! The contact must be connected to ground, and not to the negative terminal of the battery! Otherwise, if there is a breakdown, there is a risk of the battery exploding. The control should have an incandescent lamp, not an LED.

Possible faults

At the beginning of the article, the main reasons were described, but there are also some more rare malfunctions.

Worn contact of the resistive throttle position sensor. The ECU cannot adequately calculate the amount of air and the desired load.
A stretched timing chain, which causes the valve timing to shift.
Failure of the DPKV crown damper. Wear leads to uneven rotation of the crown, which can be interpreted by the ECU as a problem with the combustion of the working mixture.

Recommendations for checking and troubleshooting

The first thing you should check when misfiring is the explosive wires and ignition coils (module), they often turn out to have broken insulation, a break, or an oily surface. We measure the wires with a multimeter (normal resistance is about 4 - 10 kOhm), in resistance mode, but to check individual ignition coils, you just need to swap places with a known working cylinder and clear the errors again. If the code has changed to the number of another cylinder, then the coil is faulty. The ignition module is more complicated; it needs to be checked with a tester.

The second in line are the spark plugs - a damaged electrode, incorrect gap, or oil deposits lead to failure or unstable operation of the spark plug.

Having unscrewed the spark plug for inspection, then what else can be done - measure the compression in the cylinder . Reduced or absent compression leads to insufficient compression, and therefore creates problems with ignition of the mixture.

Clogged fuel injectors provoke interruptions in the supply of fuel to the combustion chamber, but, unfortunately, without a stand it will not be possible to quickly check them. And the only thing that can be recommended in such a situation is to refuel with fuel with a higher octane number, and drive the car for some time at high speeds (4-5 thousand/rev).

A fuel filter that has not been changed for a long time or bad gasoline very often becomes the culprit for the unstable operation of the injectors. Therefore, remember the last time the filter was changed, and at what gas station you filled it with fuel.

A stuck EGR valve or leaks through the intake manifold gasket , which can also cause random misfires, can be difficult to determine on your own, so when doing computer diagnostics, pay attention to such a parameter as long-term fuel correction . It will show how much the ECU compensates for the imbalance in the air/fuel ratio. When this parameter on a particular cylinder differs by more than 10%, this may indicate a vacuum leak or air leak.

More rare cases that cause a violation of the ignition order, such as disrupted valve timing or a violation of the exhaust gas outlet , are controlled by the control unit and, in addition to the P030X code, other errors will appear regarding the catalyst, lambda probe, camshafts.

I hope all these tips will help you not only figure out the cause of the malfunction, but also fix it yourself, without outside help, without spending a ruble, or pay only for a specific part, and not waste money on replacing everything that can fail .

Posts: 7

From: 52

lada

March 20, 2010, 11:03 #1 123

Help with advice! mileage 80 thousand the third cylinder failed, what could it be?

Posts: 2206
Lada Priora

Error code P0303 – misfire detected in cylinder 3