Why does the carburetor of a VAZ 2107 engine troit when cold?

Timing marks

If the camshafts are incorrectly aligned relative to the crankshaft

– the reason for the engine tripping. The opening and closing timing of the intake and exhaust valves will not coincide with the engine strokes.

For example, at TDC of the piston the valve may be closed, so a flash will occur not only in the cylinder, but in the intake or exhaust manifold, depending on which valve is not closed.

This may occur due to a stretched timing drive.

. As the chain or belt is used, it stretches. Therefore, the opening or closing angles may shift. This leads to engine tripping.

What to do

If you have checked everything: the spark plugs are in order, there is a spark everywhere, the quality of the mixture is at the right level, you need to check the timing marks. We look at the degree of belt tension. In the case of a chain, how “out” the tensioner is. If the marks are knocked down, then we set them as needed.

After troubleshooting, we fix the problem. If the motor stops running, the cause has been found and eliminated.

Distributor and capacitor

If the problem is in the capacitor on the distributor (and it can either fail completely or partially), then the engine will start and can operate properly and stably at idle speed. But while moving, the unit will twitch. This indicates a damaged capacitor. Remove the cover from the distributor, move the slider so that the contact opens. How is it checked? Turn the slider by hand to open the contact.

During the opening process, a spark should jump. If the capacitor is damaged, it will be blue and quite strong.

Also, the distributor may have insufficient or excessively large gap in the contacts. This causes unstable operation of the motor. The rod may wobble from side to side. It has cams and a slider installed. The contacts will open without much clarity, which will cause interruptions. The rod bushings or the entire distributor should be replaced.

What to do if the engine fails? We diagnose and repair!

As many people know, an internal combustion engine is a rather complex mechanism that needs to be regularly maintained and repaired from time to time. Otherwise, some problems may appear during operation. Drivers often feel that the engine becomes more difficult to start, its power decreases, gasoline consumption increases, unusual sounds and vibrations arise, and the engine begins to operate unstably.

You need to remember that if the engine of a VAZ 2107 is misfiring, this is a serious breakdown that needs to be fixed urgently so as not to lead to more complex problems. In this article we will discuss how the breakdown manifests itself, what the causes may be and how to eliminate them.

Misfires - what is it?

Let's start with what is a cylinder misfire? This phrase means a situation where in one of the cylinders the ignition of the fuel mixture occurs late or slow. Simply put, the “acceleration” of the piston in some of the cylinders is slower than in the others. As a result, there is a violation of the synchronization of the engine, the engine runs unevenly, jerking occurs, fuel consumption increases, and the dynamics of the car decreases so much that even a small hill becomes a big test. In addition, in cars equipped with an ECU, a corresponding error appears on the display in the form of a code, for example “P0304” - misfire in the fourth cylinder. The last digit in the code corresponds to a specific cylinder.

Troubles the engine of a VAZ car. What to do?

The impetus for writing this post was a real repair at the request of a client, which consisted of a simple replacement of the vacuum booster, but isn’t it true that the engine may be tripping for the wrong reasons... In this post I want to consider the main reasons for this most unpleasant phenomenon, as well as methods for diagnosing and troubleshooting repair.
Let's start with the signs that the engine is running rough. “Engine trouble” - by this we mean that one or more cylinders are not working. Accordingly, the engine does not develop full power, does not have the necessary traction force, fuel consumption increases... But we all already know this, closer to the point.

VAZ 2107 engine troubles: causes and solutions

The sound of a VAZ 2107 engine revving is difficult to confuse with something. The car begins to make a characteristic intermittent knock, which indicates that only three of the four cylinders are working. The reasons for this, as well as the consequences, can be very different.

Main symptoms of a malfunction

The number of working cylinders decreases, and a decrease in power is immediately felt; the car no longer pulls as well as before. Vibration appears even at idle, and a characteristic trembling can be heard from the engine compartment. You may notice that fuel consumption has increased, and the smell of gasoline can be clearly felt in the exhaust gases.

If measures are not taken in time, a major engine overhaul may be required. And it’s not like changing a carburetor; it requires a lot of money and time. A mixture of gasoline and air is burned in the cylinders. If this does not happen in one of the cylinders, then the fuel accumulates and gradually mixes with the oil, going into the crankcase. Because of this, the viscosity deteriorates significantly, and lubrication ceases to have the desired effect. As a result, the piston and rings wear out to a critical state. In addition, the cylinder walls are erased. The VAZ 2107 engine needs repair.

Causes of cylinder failure

If the VAZ 2107 engine fails, there may be several reasons for this, and in order to find the fault, you need to perform several actions:

• find the faulty cylinder;
• check the spark plugs;
• inspect the wires, injector, injectors, valves;
• check air leaks into the carburetor;
• check operation hot and cold.

Identifying a failed cylinder is quite simple. When the machine is running, you need to remove the high-voltage wires one by one if a carburetor is installed. At this moment, no current will be supplied to the spark plug and the cylinder will stop working. The injector is simpler in that you don’t need to risk disconnecting the wires; it will be enough to remove the chips responsible for controlling the fuel supply. If nothing changes and the engine continues to operate without changes, the faulty cylinder has been found.

The next step is to check the spark plug. Having unscrewed it, you should carefully inspect it. If there is carbon deposits on it, then because of this the spark will not “break through”. It is a mistake to believe that replacement or simple cleaning will solve the problem. Without finding and eliminating the cause, a new candle will take on the same appearance in a short time.

You need to check for spark. To do this, you need to put a high voltage wire on it and bring the metal end to the engine housing. Next, someone needs to crank the starter several times. If everything is normal, a spark should appear. If it is missing, this may indicate:

• wire break or high resistance;
• failure of the ignition coil;
• malfunction of the electronic control unit;
• failure of the crankshaft position sensor;
• The belt is offset by several teeth.

If the spark is fine, but the car still does not pull, and you can clearly hear that the engine is shaking, the reasons may be the following:

• compression is broken;
• defects have arisen or the rings have worn out;
• problems with injectors;
• abnormal valve operation.

The cause of a non-working cylinder may be an injector or failed injectors. This may be a consequence of driving on low-quality gasoline or using homemade fuel system cleaning devices. Sometimes a breakdown is indicated by the fact that the injector has failed, but this is very rare.

Also, the VAZ 2107 engine malfunctions due to the fact that the injectors simply become clogged and it is enough to clean them. There may be a break in the power or control circuit to the injector, sometimes a short circuit occurs. It is advisable to carry out a diagnosis. Even if it does not reveal any error, this indicates that the reasons are mechanical.

There are frequent cases when the VAZ 2107 engine stalls when cold or hot. The first thing that comes to the specialist’s mind is that the valves need to be adjusted. It is recommended to perform this procedure every 20,000 km.

The term “cold” means that there are large gaps at the valves, and during prolonged operation, even at idle, the metal heats up and expands, and everything returns to normal. “Hot” means the reverse process. Before heating, all elements are within normal limits, but after heating, the valve jams.

If the engine of a VAZ 2107 fails, but the car does not pull, then you need to immediately find the cause and eliminate it. Otherwise, the consequences can be extremely sad and quite costly.

Five signs of tripling

It is very important that the fault is diagnosed in a timely manner. Then you need to isolate the problem as quickly as possible so that repairs can be made.

So, if the VAZ 2107 engine has trouble with the carburetor, the reason for this may be the malfunction of one of the cylinders. Sometimes several cylinders fail at once. In fact, this is due to the fact that for some reason the working mixture does not ignite in the combustion chamber of an idle cylinder, or it does not burn completely.

We list five signs of engine tripping in a VAZ:

1. At idle, the engine begins to twitch and shake. Sometimes the shaking becomes so powerful that the vibrations are felt throughout the body, transmitted to the steering wheel and even to the gear lever. With such strong vibration, we are most likely talking about a complete failure of one of the cylinders.
2. The engine power noticeably disappears, the driver feels the gas pedal sink, jerks appear during acceleration, and fuel consumption increases. The check engine light may come on. Of course, these problems also appear with other malfunctions. But this is exactly how tripling manifests itself.
3. The engine speed begins to float or jump. RPM fluctuations can be either minor or quite large.
4. If you look at the electrodes of the spark plugs, you will notice black carbon deposits. Of course, this may indicate a malfunction of the spark plug itself. But if, after changing the spark plug set, carbon deposits appear again in the near future, then there is another reason for the breakdown.
5. The exhaust system begins to operate with sound “jerks” that transmit vibration to the body.

Even if you notice only one of these symptoms, you urgently need to understand what was the source of the breakdown. The point is that equipment failures cannot be ignored. After all, delay can lead to more serious problems that will require expensive repairs.

Where to look for the cause of cylinder failure

Important! You will have to look for the cause of engine cylinder failure in a garage. There are two possible ways here: check the mechanics or the electrical, that is, the ignition

Let's start with the simplest thing and diagnose the electrical system.

Spark plug. Let's use a proven method to check their functioning. Look at the side electrode and insulator, their color should be light brown, not black. There should also be no soot. If there is soot, it means the mixture is over-enriched or there is oil on it. Now let's start checking sparking. Place the spark plug on the high-voltage wire, and then bring it to the cylinder block, the distance between them should be 1-2 cm. Turn the starter. Did the spark travel that distance? This indicates that the spark plug is working properly, otherwise it should be replaced.

BB wires. They may be damaged

How to check this? Pay attention to the tip of the high-voltage wire. Did you see a light gray coating on it? This means he is operating at his limit.

Use a special multimeter to check the resistance of the high-voltage wire. Please note that depending on the motor, the wire length and resistance may vary. When there are no additional instructions, 20 kOhm is taken as a constant resistance value. If this value is exceeded, then the problem is in the high-voltage wire.

Distributor. When the spark plug does not work properly, a breakdown occurs in the ignition distributor cap. In this case, it is necessary to diagnose the ember; stretching the spring will also help.

High voltage wires are mixed up. If a cylinder failure occurs, the cause may be in the explosive wires.

Now let's check the mechanics.

Injector. A malfunction in its operation may be one of the reasons for the failure of the cylinder. For example, an injector is broken, the injector is clogged with a poor quality fuel mixture

Note! Damage can result from the use of the latest fuel purifiers, which can be purchased at any specialized auto store. It is best to diagnose and clean the injectors at a trusted service center.

Gas distribution mechanism

The fuel mixture enters the cylinders in the wrong quantity and quality. This can happen for various reasons. For example, the timing belt was installed incorrectly, the tensioners or oil seal became unusable. The camshaft may also break, or the hydraulic lifters may need to be replaced.

Because the engine constantly overheats, the cylinder head gasket may burn out. This happens because the car owner does not monitor the antifreeze level or drives the car at high speed.

All of the above can cause the cylinder to fail. By the way, not everything that can lead to such a breakdown is listed here. Only by understanding why one cylinder in the engine failed will you be able to eliminate the problem. You can do this yourself or by visiting a specialized service center.

Why did the engine start to stall? – The most complete analysis of the reasons

What does the term “Engine Troit” mean? I ask this question at the beginning of the article in order to cut off the “couch experts”, and only real car enthusiasts who love and appreciate their car remain here.

Just one of the commentators began to assert:

“Engine tripping is when there is no one cycle in the operation of an internal combustion engine. That is, out of four cycles of engine operation, one cycle was thrown away.”

I explained to him that he was wrong, but he didn’t get it. To prevent such armchair army specialists from wasting their time and “cracking” in the comments, I want to cut them off right away.

Why the car engine started to misfire - the most common reasons

Now let's continue the conversation with real car lovers.

Today we will look at the main reasons why the motor may trip. They may seem banal, but read my work to the end carefully, I am sure you will learn something new for yourself.

No spark on cylinders 1 and 4 of the VAZ 2114: troubleshooting

The reasons why cylinders 1 and 4 of the VAZ 2114 do not work may be:

1. Candles.
2. Wires.
3. Ignition module.
4. Control block.

We talked about how to check the spark plugs above, so let's move on to the wires. To check, you will need a tester (multimeter), with which you should check all high-voltage wires (you should measure in ohmmeter mode).

The resistance of all four wires should be approximately the same and not exceed 200 kOhm. If the resistance is significantly higher than specified or the resistance of some wires is very different from the resistance of others, then they should be replaced with similar ones.

Checking high-voltage wires with a tester

If the wires are in good condition, we proceed to checking the module.

To check it, you should use a self-diagnostic scanner connected to a laptop or smartphone (the connection can be via Bluetooth, Wi-Fi, or a USB cable).

The scanner displays the test results on the screen of the mobile device using standardized codes.

Auto diagnostic scanner

The most common of them (indicating that the ignition module is damaged) are the following:

• P3000, P3001, P3002, P3003, P3004 - no spark in the cylinders (the last digit is equal to the cylinder number). In our case there should be signals P3001 and P3004;
• P0351 - a rupture occurred inside the ignition module on the windings responsible for cylinders 1 and 4;
• P0352 - the same thing, but the break occurred on the windings of cylinders 2 and 3.

If the above errors are detected as a result of the scan, then the module is burnt out and should be replaced with a new one (since it is not a repairable component).

High voltage wires

The tips and the wires themselves are suspect. Due to harsh operating conditions, they may lose elasticity and dry out. I have witnessed more than once when they were changed, they did not align, lying on the table, they remained the same shape as on the car.

Plus, poor manufacturing quality leads to microcracks appearing on them. The high discharge penetrates them. In such places, a light spot with black dots or soot streaks forms. It is best seen in the dark with the engine running. You can observe sparks at the breakdown sites.

There is another way to check high-voltage wires, it is shown in the video:

This is fraught with poor sparking. The spark will be weak or absent altogether. The cylinder will stop working and the engine will stall.

What to do

Only replacement of armored wires with new ones. They cannot be repaired. If you have successfully done this, write in the comments how you did it and what the result was.

Diagnostic methods

When you find out that the motor is not working, you should diagnose it. This is the only way you can find out which cylinder failed and why. You can do this yourself, or go to a car service center. There the engine will be checked using a computer. However, most often you will be able to find out on your own why the engine is tripping. However, if there is a cylinder failure, and the reason is a decrease in compression, you should find a competent specialist who will solve your problem.

Act one. We find the cylinder that failed. To do this, we diagnose the engine after it starts. Be extremely careful when performing this work. Turn the ignition key, the hood should be open. Let's listen to the sounds coming from the engine compartment

Pay attention to how the engine works. Now, one by one, we disconnect the explosive wires that go to the spark plugs.

If you disable a cylinder that is working properly, the engine will run rough. If a cylinder fails after the spark plug is disconnected, the power unit will operate without changes.

How else can you perform diagnostics? We do not touch the explosive wires. We simply turn off the chips one by one that control the fuel supply from the injectors to the cylinders. If you disconnect the chip, but the motor runs without changes, it means that this cylinder has failed.

Act two. We carry out diagnostics of explosive wires, as well as spark plugs. First of all, you should disconnect the wire and carry out an inspection. Is the insulation damaged? This indicates that the problem is in the BB wire. Then we check whether the conductive core is intact. Did you find that it has kinks or is burnt out? This means that a breakdown or internal resistance may occur. To measure it, use a multimeter. The data obtained must satisfy the acceptable readings. Otherwise, current will not flow normally to the spark plug.

Did you find out that everything is fine with the wire? Then we unscrew and diagnose the spark plug.

Is the spark plug base or its electrodes deformed or do they have carbon deposits on them? A new spark plug needs to be installed. If everything is fine with it, then the reason for the engine tripping is not a cylinder failure.

Act three. We determine how much air penetrates the cylinder. If it is not enough, then the fuel mixture will be over-rich, which means the engine will start to stall. The air supply system must not be depressurized. To check whether this is so, you should shut off the intake pipe, and then use a compressor to supply air into the cylinder through a vacuum hose. Supply pressure 0.5–0.7 atmospheres

Pay attention to the sounds you hear when doing this. Is there a hissing sound? This indicates that the air supply system is leaking.

How else can you diagnose the engine for breakdowns? Examine the air filter. When it becomes clogged, no air can enter the cylinder. We inspect the throttle sensor, as well as the mass air supply sensor. To carry out such diagnostics, you will need a computer; it should be connected to a special connector.

Act four. We find out what volume of the fuel mixture enters the cylinder. For this purpose, you will need to measure the pressure in the fuel system (no more than 7 atmospheres). Use a pressure gauge. It must be connected to the injector ramp. To find out the pressure, you will need to measure it in four different operating modes of the engine: when you turn on the ignition, then at idle speed, at operating speed, when the tube is removed from the pressure regulator and the check valve tube is pinched.

Have you discovered that your blood pressure is insufficient? Most likely, the fuel pump or pressure valve in the fuel system has broken down. Is the pressure normal? Then, perhaps, the injectors are faulty or dirt has accumulated in them. At the end of the test, we diagnose the functioning of the fuel system using special equipment. Most likely, you will find errors in the electronic control unit.

Act five. Using a compression meter, we find out what the compression is in the cylinder. This device should be inserted into the spark plug hole of the cylinder that has failed. Then turn the ignition key and increase engine speed. Record the received data 2-3 times. Did you notice that the compression decreased by 15%? This means that the piston in the cylinder has become unusable. The problem may also be in the piston rings or valves. To determine the cause, you will need to disassemble the motor.

Checking the EPHH needle valve.

We also remove the hose from the side outlet (fitting “2”) of the electro-pneumatic valve and connect this hose to the economizer. We start the engine. If the economizer valve is working properly, the engine should run at low speed. If the engine stalls at idle, the valve diaphragm may rupture.

To change the valve, disconnect the wires from the microswitch terminals.

2. Using a screwdriver, unscrew the two screws securing the economizer housing to the carburetor.

3. Remove the bracket with the microswitch...

4. ...as well as the economizer assembly.

5. Remove the gasket from the economizer.

6. Unscrew the two bolts holding the body and economizer cover together...

7. We halve the economizer and check the condition of the diaphragm.

If the diaphragm is defective or the needle and seat are worn, we replace the economizer assembly.

On older models it was possible to change parts individually.

We install the new economizer in the reverse order.

All answers

In fact, Volodya seems to have said everything and already asked. The only thing is that since the vehicle says that replacing the spark plugs/wires helped for a while, it means that gasoline is most likely being supplied, but either not as needed, or the problem is already in the cylinder (valve/ring).

Watching the operation of the injector, measuring compression, and the appearance of the spark plugs has not yet been canceled as a diagnostic sign.

Oh, yes... and in the future, it is advisable not to reveal an inoperative cylinder by pulling off the explosive wires, because that’s exactly what I understood from the text.

The computer will only show the time of its opening, while it may well not spray gasoline, but literally pour it. Accordingly, such a mixture will burn poorly, and the candle will quickly fail. The last spark plug change didn't help at all?

PS What kind of “hog” is this? Merc in the 140th body or what?

Good day everyone. The problem is that cylinder 4 is not working. I found out by removing the caps from the spark plugs. From 1 to 3 cylinders, the speed drops, and on 4 it does not respond at all. I measured the compression. 10; 9.5; 10; 9.5. Here. I measured the wires with a tester, resistance 4-6 kOhm. (normal) I changed the spark plug with the third cylinder, the result was the same. I haven’t yet checked the spark on the unscrewed spark plug; I was confused by the fact that when removing the cap from the spark plug, a couple of clicks were heard, as I thought it was from a spark breaking through, but I’ll check it one of these days to ease my conscience. Worth BSZ. I tried to change the cover from the old contact one. I started it, heard a crackling sound, turned it off, it turned out that the contact of the slider was hitting the contacts on the cover. Do not have another one. But visually, there is deposits on contacts 1, 2 and 3 of cylinders, it is across the entire width of the contact, in the plane of rotation of the runner, and on contact 4 of cylinders such deposits are only half the width of the contact. Visually the contacts are uniform, well, in the sense, identical. by size.

So, you press the brake, the engine holds the speed for a couple of seconds and it drops by about 200. You pump the brake pedal, the revolutions jump from 800 to 1500. This happened before, but they jumped to a maximum of 1200. I checked the VUT (pressed the pedal, started it, the pedal went further.).

My plans for now are to pull out the VUT hose that goes to the engine intake manifold, turn it off, start the engine and also pull off the cap from the spark plug. there will be changes or not.

Anyone who may have had a similar problem, please tell me what else can be checked.

And the gas consumption of 16 liters in the city and 12 on the highway is not at all pleasing. Previously it was 12 and 9.5, respectively.

Even when releasing the gas, you can hear dull pops in the muffler.

The engine troits on the suction of the VAZ 2107 carburetor

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Hello.
I have the following problem: When you start the car, everything is fine, after one or two minutes of warming up on choke, the engine begins to throttle and the speed gradually decreases even on choke (from 2000 to 1000 or less). If you remove the choke, the idle does not hold and it immediately stalls. After you use the gas pedal to warm up the engine to about 50 degrees, it gradually stops running and starts to idle. What could be the problem? VAZ 2106, V 1.6, BSZ, Brisk spark plugs, VAZ 2107 carburetor

In general, this is a malfunction of the starting device. It is necessary to check the membrane, rods, springs, sephx components (valve, block, microphone) and adjust, and adjust, and adjust. But at the same time, check the SZ - wires, distributor cap, all sorts of contacts... Such nonsense happens - that overnight water from the tank will pour into the switch, but you drive it, warm it up and everything is fine

PS Well, add idle ones. 900 should be at least when warmed up with low beam headlights. Then the cold stall will be less

Afee

Plus what
Vyacheslav Karpov
. Is there an air heating corrugation, has the damper been set to winter?

there is corrugation. The damper has not yet been moved. Can't spark plugs act like that?

It doesn’t start working right away, only a couple of minutes after starting

Candles can't act like that

They are the ones that act up (they simply “flood”), especially on cylinders 1 and 4. but this is usually a consequence and not a cause. The reason is that the carburetor is not working properly. Fuel level . Adjustment of the PU, malfunction of elements (membrane, telescopic rod) PU - insufficient lifting of the air intake when starting the engine - over-enriched mixture.

It doesn’t start working right away, only a couple of minutes after starting

There is nothing surprising here. the reasons are the same as above. + diffuser freezing due to lack of air heating.

Well, for prevention, it wouldn’t hurt to check the spark (for power) and measure the explosive wires for resistance.

What inconveniences await you in winter without this air heating?

I have the following problem: When you start the car, everything is fine, after one or two minutes of warming up on choke, the engine begins to throttle and the speed gradually decreases even on choke (from 2000 to 1000 or less). If you remove the choke, the idle does not hold and it immediately stalls. After you use the gas pedal to warm up the engine to about 50 degrees, it gradually stops running and starts to idle. What could be the problem?

Is air heating very important in winter?

The effect on the eighth family is not as significant as on the classic due to the location of the units under the hood being different from the classic. But the carburetor still freezes without heating the air. The car refuses to go (in higher gears) above a certain speed threshold. The engine begins to stall, lose speed, run intermittently, after releasing the gas and running the engine for a short time at idle or at low load, everything is restored. and so on in a circle. In the urban cycle it is almost unnoticeable. It appears mainly on the highway.

Source

Ignition module or coils

Some vehicles may use an ignition module or individual coils for each spark plug. Their failure also leads to tripping of the power unit.

There is no spark - the air-fuel mixture in the cylinder does not burn.

How to check

If the engine starts to leak, remove the caps from the spark plugs one by one. We move it a little away from the central contact of the spark plug and observe whether there is a spark between them. If there is sparking on all spark plugs, the ignition module is working.

The malfunction of individual ignition coils can be checked with a multimeter, but this is the topic of another article, or using a scanner. Diagnostics will show misfire on one cylinder. In this case, the coils can be rearranged. If the misfires “move” to another cylinder, then it is she who is to blame.

It happens that at idle speed or low loads the coil works properly, it manages to ignite the mixture efficiently. At maximum, misfires may occur, it does not have time to produce a spark.

Causes of malfunction

Why does the engine in the VAZ 2107 suffer from injector problems?

If the driver observes signs of malfunction in the operation of the cylinders, it is necessary to diagnose the operation of the power unit. There are five most common reasons:

• problems with the ignition system;
• violation of the formation of the working mixture;
• malfunction of the gas distribution mechanism;
• malfunction of the power steering system;
• failure of the engine itself.

I would like to say right away that there may be many more reasons. And without high-quality diagnostics, it is not always possible to determine exactly what the problem is. But in this article we will discuss the most common faults in most cases, which in 90 percent of cases drivers can detect and fix on their own.

Common causes of floating revolutions

So, we figured out the main symptoms. Now let's move on to the reasons. Let us immediately note that floating idle speed is often a problem with injection engines. The fact is that a complex ECM system is responsible for idling in this case.

This system assumes the presence of a controller, sensors and actuators. The control unit receives signals from sensors and transmits commands to actuators (for example, IAC), maintaining stable engine speeds at idle and other modes, regardless of the load on the internal combustion engine.

Article on the topic: Disadvantages of the DSG gearbox: what you need to know

However, any failures that are associated with the supply of air, fuel, a violation of the composition of the working fuel-air mixture or its ignition, as well as various mechanical breakdowns will lead to floating speed.

It turns out that you should start checking with the throttle assembly, sensors and actuators. The ignition system, idle air regulator, mass air flow sensor also need diagnostics; it is necessary to assess the condition of the fuel and air filters, injection nozzles, etc.

As a rule, in practice, the idle air regulator causes a lot of problems for drivers. In fact, this is a stepper motor that has a conical locking needle. When the throttle valve is closed, air bypasses the valve through a channel that is closed by the needle.

If malfunctions occur in the operation of the device, the ECU is not able to correctly “select” the mixture composition at idle, as a result, the speed floats.

The mass air flow sensor also deserves special attention. During operation, the air flow sensor may become dirty or break down.

One way or another, the ECU does not receive correct data on air flow, which leads to disruption of mixture formation and jumps in engine speed.

Often, a floating engine speed can be associated with severe contamination of the throttle valve itself or mechanical breakdowns of the throttle, damage, or deformation. The damper may jam and not close completely.

To prevent such complications, it is necessary to periodically clean the throttle from dirt, and on many cars, additional training of the throttle is required after cleaning.

During diagnostics, you should also check the crankcase ventilation valves. Normally, crankcase gases are redirected to the intake, where they are mixed with air and fuel, after which they are burned in the cylinders.

On engines with mileage, a lot of crankcase gases accumulate due to natural wear and tear of the CPG. An excessive amount of such gases leads to a violation of the composition of the mixture if the crankcase ventilation valve jams. This is also a common reason why engine speed fluctuates.

By the way, if you touch on carburetor engines, the speed on the carburetor floats, usually due to the settings and adjustments of this device being messed up. Also, one should not exclude the possibility of a breakdown of the carburetor solenoid valve or clogging of the idle jet.

Let’s also add that if the speed of a diesel engine fluctuates, this is often caused by rust on the fuel injection pump blades. Corrosion occurs due to the presence of water in diesel fuel.

Causes of “triple tripping” of a VAZ car engine

• Incorrect ignition timing
• Air leak in the vacuum brake booster system
• Spark plug fault
• High voltage wire breakdown
• Capacitor failure
• Loss of tightness in the intake manifold area (intake manifold, carburetor)
• Burnout of valve, piston
• Broken piston rings
• Incorrect valve adjustment
• Destruction and wear of rockers (valve levers)
• Cylinder head gasket failure
• Wear, hardening, destruction of valve stem seals
• Very low fuel quality
• Incorrect carburetor adjustment
• Wear of distributor shaft, rotary plate bearing
• Loss of tightness of the membrane of the vacuum ignition advancer
• I do not take into account the use of spark plugs that are not suitable for the engine and other “faults”.

Perhaps not all the reasons, but what I could remember, if you have anything to add, then write in the comments.

Important!

You can determine a bad cylinder using a simple, old and reliable method - one by one removing the high-voltage wire from the spark plug. You have to be very careful here, because you can get electrocuted! To carry out this manipulation more safely, you need to stand on a dielectric (rubber, wood), take a clean, dry rag, remove it by the wire, and not by the cap, and do not touch the car body at this time. It is very easy to check; use a choke to increase the idle speed to 1500 rpm and remove the caps from the spark plugs one by one. If the speed drops when the cap is removed, then the cylinder is working; if there is no difference, then the cylinder is not working.

Well, now let's talk about each of the reasons in more detail.

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1. Incorrect ignition timing. With this option, I personally know not a tripping, but a seemingly slamming of the engine (missing), which is accompanied by “bouncing” of the entire engine. This is especially noticeable at idle; as the speed increases, the skips disappear. Most likely, your ignition is set too early; this may also be indicated by jerky cranking of the engine by the starter when starting.
2. Quite often, the cause of engine tripping in a VAZ of all models (except for the VAZ 2101, which does not have a vacuum brake booster) is a loss of tightness in the hose, diaphragm, or valve. As a result, excess air appears in the intake manifold, which leads to over-leaning of the mixture and misignition of the mixture in the cylinder, as a result of which the spark plug may become wet and stop igniting the compressed mixture.
3. A faulty spark plug is one of the most common causes of engine misfiring. There is nothing special to tell here, it is important to remember and replace spark plugs regularly, and the presence of a spark on an inverted spark plug at atmospheric pressure does not indicate its full functionality, because ignition occurs under much more difficult conditions (Za Rulem magazine, dating back to Soviet times).
4. At this point I will combine the breakdown of the high-voltage wire and the capacitor on the contact ignition system. A wire breakdown can be determined by replacing all the wires, as well as the capacitor. You can also try to determine the breakdown of the wire by looking at them in complete darkness; if there is a breakdown somewhere, you will see flashes.
5. Loss of tightness in the collector area, as a rule, does not occur on its own. More often this happens due to incorrect assembly or bad gaskets. I also had a case where they complained about trimming at idle. The reason was the elimination of the vacuum ignition advancer and the unplugged vacuum tube on the carburetor.
6. As a rule, when a piston or valve burns out, the cylinder stops working altogether or does not work for a long time. It can only be determined by measuring compression and opening the engine.
7. Breakage or sticking of piston rings is also not a very common occurrence, because a number of conditions are necessary for its occurrence. You can check it by measuring the compression; if it turns out to be low, then eliminate cylinder head malfunctions in a simple way - pour a little oil into the cylinder; if the compression increases, then there is a malfunction in the piston system.
8. With incorrect valve adjustment, everything is already clear - any valve may not open or close completely. Proper valve adjustment can cure this problem. Rocker wear can cause a similar problem. The valve stops opening correctly and the cylinder stops working.
9. Well, now let’s briefly go over the problems that may arise with the distributor. Quite often, on not new machines, wear of both the shaft itself and the bushings in which it rotates occurs, as a result of which it becomes impossible to establish an adequate gap between the contacts. The same thing happens if the swing plate bearing is worn out. Also, misfires can occur due to depressurization in the vacuum ignition timing advancer, where the membrane may fail.

Here I have written a few reasons why a VAZ engine may be tripping, if you want to notice or ask something, write below in the comments!

Troubles the VAZ 2107 injection engine: causes and treatment methods

The VAZ family of cars, especially older generation injection engines, are famous for causing a malfunction such as tripping. Why this effect occurs and how to deal with it will be discussed in this article.

Comparative fault characteristics

If we compare the reasons why the engine troits. You can notice some features in different VAZ models. Unlike the classic VAZ 2107, version 2114 has additional sensors and an electronic control unit. In this car, the reasons that the engine is misfiring may be expressed a little differently, namely:

• Electronics supplies an overly rich fuel mixture to cooled gasoline when the engine warms up;
• Despite the fact that the spark plug reacts to starting, in fact, it may be faulty;
• A malfunction may cause moisture to enter the ignition coil or high-voltage wires;
• Wear of piston assembly elements.

The presented nuances are not the entire list of problems that cause the engine. For example, at idle speed, the list of reasons why a VAZ 2107 carburetor engine may stall is replenished with the following options: poor adjustment and excessive compression of valves, installation of a timing belt without matching the marks, piston burnout, disturbances in the cylinder head or ECU system.

Possible causes of malfunction

If the engine of a VAZ-2107 fails , several circumstances may contribute to this. And in order to remove the malfunction, you should perform the following actions:

1. Find which specific cylinder is faulty.
2. Check all spark plugs for functionality.
3. Inspect all wires, injectors and valves.
4. Check how the air intake into the carburetor works.
5. Check the operation of both the hot and cool engine.

Finding which specific cylinder has failed is easier than usual. To do this, while the motor is running, remove the high-voltage wires one by one. But this can only be done in this case if the engine on the VAZ-2107 (carburetor) is troublesome. Of course, it will not be possible to find the cause of the breakdown, but it will certainly be possible to find a non-functioning cylinder.

Once you remove the high-voltage wire that you need, voltage will not be supplied to the spark plug, and therefore the cylinder will not work.

The next step is to check the spark plug for functionality. First, after removing the candle, you need to carefully examine it. If carbon deposits are clearly visible on the spark plug, then most likely that is why the current is not getting through. By the way, many car owners believe that it is quite easy to replace a spark plug with a new one. But in essence, this method will eliminate the problem only temporarily. It is necessary to find the reason why the candle acquired such an appearance.

Do you have Troitis?! TROIT. (BONUS about Nulevik)

Very often they ask the question - Why does the car stall

? What's the matter? How to solve such a problem? Let's look at the next one.

Checking the distributor

And then we will check the VAZ 2106 distributor. The first thing you need to pay attention to is its cover. We remove it and inspect it for damage, cracks, etc. Through cracks, along the path of least resistance, current can flow to ground

Thus, a small voltage will already come to the spark plug or nothing at all will come, and the spark will either be weak or not exist at all

Through cracks, along the path of least resistance, current can flow to ground. Thus, a small voltage will already come to the spark plug or nothing at all will come, and the spark will either be weak or not exist at all.

Next we will talk about the remaining parts of the distributor. And they need to be considered in the event that you do not have a spark at all, or if you have one, but it is very weak. Those. if there is no spark in only one cylinder, then there is a 99% chance that the problem is not in the distributor.

After the lid, we immediately pay attention to the slider. The runner must also be intact and not have any damage. Moreover, you need to inspect it both from above and from below.

And the best way to do this is to unscrew it

Moreover, you need to inspect it both from above and from below. And the best way to do this is to unscrew it.

Next we move on to the breaker contacts. First you need to check the cleanliness of the contacts. If there is any plaque or carbon deposits, it naturally needs to be removed. It would probably be better to do this with zero sandpaper or a needle file. Next, after cleaning, you need to check the gap between the contacts. It should be 0.35-0.45mm

We take a set of probes, find a 0.35 probe and check... We also pay attention to the cams that move the contacts - they should not have significant wear and the existing wear should be the same for all cams

Next you need to pay attention to the wire that is connected to the breaker contacts. It is advisable to move it, tug it in different directions, and make sure that the wire has reliable contact. It may happen that over time, due to vibration and other things, this wire breaks off and, naturally, the contact will either be very weak or disappear altogether

And this is not often paid attention to

It may happen that over time, due to vibration and other things, this wire breaks off and, naturally, the contact will either be very weak or disappear altogether

And this is not often paid attention to

The next logical step is to check the capacitor. The simplest thing is to measure its capacity. It should be within 0.25 µF. But for this, of course, you will need a tester with a capacitance measurement mode. I don’t have this, so I’ll tell you about the second method. We disconnect the capacitor wire and the wire coming from the coil from the distributor breaker and connect a light bulb (12V) between them. Afterwards, turn on the ignition and look at the light bulb - if it is on, it means the capacitor is broken and needs to be replaced. If it doesn’t light up, then everything is fine with the capacitor.

In the same way you can do without a light bulb. Instead of connecting the light bulb, we simply short-circuit the wires with each other, with the ignition on, of course. If it sparks, the capacitor is broken.

Reason one - spark plugs

I wrote in detail about how to determine faults in car systems using spark plugs here .

I recommend reading it - it turned out to be useful, judging by your reviews, thank you.

We unscrew the spark plugs one at a time and look at their insulator. If it is covered with dense carbon deposits, then it is difficult for a spark to penetrate it. The current seeks the path with the least resistance, so the spark will not be between the electrodes, but will “go” along the insulator to the side. Its energy will not be enough to set fire to the air-fuel mixture. This cylinder will not work.

Heavy carbon deposits on the spark plug electrodes may cause the engine to trip.

We inspect the external condition of the spark plug insulator. If there are microcracks, then part of the current will not be converted into a discharge, but will escape through these damages. You need to look at the internal insulator, which is screwed into the cylinder head, and at the external one, onto which the armor wire cap is placed.

Any chips or damage can lead to poor sparking or its complete absence.

A superficial breakdown of the spark plug insulator is one of the reasons why the engine began to fail.
A large or small gap between the electrodes. Many people have heard or know that for certain engines, ignition systems and types of fuel used, spark plugs with a certain gap are required. Usually its value is indicated by the manufacturer of engines and cars.

In order for the spark plug to work well and the engine not to stall, a certain gap between its electrodes is needed

How to check the spark without special devices on the engine

This is an old, “grandfather” method, some people are afraid of it:

• They unscrewed the spark plug;
• They put an armored wire on her;
• They leaned it with the inner body, the metal part, against the engine;
• Turn on the ignition and turn the starter.

Be sure to hold on to the rubber cap of the armored wire, otherwise your hand will shake violently. This is what many are afraid of