When you hit the gas hard, the engine jerks. Why does the car twitch Niva twitches when you press the gas injector

Sooner or later, every motorist has to deal with the following problems:

The appearance of malfunctions in the operation of valves;
Sharp jerks of the car (there is a feeling that it is twitching by itself);
The lack of an instant response of the motor to pressing the gas pedal.

Moreover, when you press the gas pedal, the car starts to twitch not only when idling, but also during acceleration and at full speed of the vehicle. To understand how this happens, what is the reason and what needs to be done to correct the situation, it is necessary to move from the symptoms to the causes of the breakdown.

The main reason for the "jerking" of the car when you press the gas pedal

The main cause is most often associated with an oxygen-enriched / depleted fuel mixture. It is because of the lack of air that the crankshaft continues to rotate despite the fact that the gas pedal has long been released. In addition, when the pedal is pressed hard, the motor starts to twitch and rotate in place.

The root cause of the problem is the preparation of the wrong mixture. In turn, the mixture can be supplied to the engine in different ratios due to a malfunction of other devices and components of both the engine and the fuel system.

Jerking of the car due to a malfunction of the TPS

The second sensor that affects the air supply to the system is a device for adjusting the mass flow of oxygen in the system. It works in the injection type of engines and is responsible for the air supply during the formation of the fuel mixture. If this component is defective, then your car will also twitch, without even having time to accelerate. The solution is similar with the first sensor - dismantling and complete replacement of the DMRV.

Jerking the car - a malfunction in the carburetor chamber and pump

In the event that the engine starts to jerk in carburetor machines even with a slight pressure on the gas pedal, the focus should be on the carburetor chamber. The problem is often associated with clogging of the outlets, which are located in the first of the carburetor chambers.

The fuel, having entered the motor, takes with it part of the burning and metal chips, as a result of which the mixture undergoes changes, and the motor is unstable. You can solve this problem yourself - just remove the carburetor and blow out all its pipes and holes with compressed air.

A classic example is the following situation: when replacing the front hub bearing on a VAZ-2109, the pump was damaged. As a result of the failure of the accelerator pump of the carburetor, the mixture is supplied to the engine in an incomplete volume. The result is the appearance of jerks during even a smooth attempt to start. In most cases, it is not advisable to repair pumps, which is why they are simply changed in a car service.

carburetor chamber

Vehicle jerking during acceleration

Such a problem can manifest itself with a smooth set of revolutions, which is accompanied by a sharp short twitching of the vehicle. In this case, the reason is related to the lack of a constant supply of the fuel mixture to the float chamber of the motor. That is, the fuel is burned in the chamber much faster than the fuel pump overtakes a new stream. As a rule, a breakdown can be found precisely in the design of the fuel pump.

The solution to a fuel pump malfunction takes place in 3 stages:

Remove the top cover of the pump and carefully inspect the surface of the hole where the valve structure should be located;
If the sealing ring is worn or missing, fix a new one;
If during the diagnostics a depressurization of the chamber is detected or the problem is related to interruptions in fuel injection, then the final stage will be associated with the complete replacement of the inoperative valve and the further restoration of the tight state in the system.

Advice: when repairing, do not try to repair holes in the old cylinder and install it in place. In the future, this can lead to a major overhaul of the entire engine structure.

fuel mixture

The appearance of jerks in the car when you sharply press the gas

If the cause is not related to the fuel pump, then these symptoms may indicate the so-called “triple” of the motor. In a car, a situation arises in which only one of the 4 cylinders can work correctly. As a result of “triple” the motor simply cannot respond in time to pressing the gas pedal, after which similar problems arise. You can deal with the breakdown in the following ways:

If the oxygen supply sensor does not work properly, the system is diagnosed using a multimeter. In the event of a malfunction, it is simply replaced.
When the valve timing is shifted in the motor, it is necessary with the help of car service specialists to adjust them according to the appropriate instructions.
The detection of an incorrect glow number of candles is solved by installing a new kit with the correct number.
The problem of nozzle clogging can only be solved in a car service. To do this, they are installed on a special stand that simulates the operation of the motor, and washed with a special solvent.
Also, a problem may arise when the emulsion tube and well located in the design of the second chamber of the carburetor motor are clogged. The only solution here is to flush the carburetor and tube with kerosene.

Engine jerks due to problems with the ignition system

If, when the car accelerates, you observe sharp dips in power, then the reason lies in the malfunction of the elements of the ignition system. This problem applies to any type of engine. The only correct solution is to check the ignition with the engine off. Conducted by the following features:

The tightness of the fastening of the pads with wires is checked;
No chips and good condition of the coil;
The serviceability of the wiring connecting the ignition system to the engine.

After checking all the elements, you need to start the car and just listen to how the engine began to work. If you find the appearance of characteristic clicks, then there are small breakdowns with high voltage in the system. In this case, you will have to buy all the elements of the ignition system - a coil, a block and a set of high-voltage wires.

Advice: do not attempt to change the wiring on the machine yourself. Only highly qualified specialists can correctly connect relays and fuses using instructions and diagrams, after which the ignition system will not burn out. You can also check the wheels at the same time by comparing the indicators in the tire pressure table of the car.

In the case of smooth engine operation, the problem may lie in the candles. And ate to speak more precisely - in the absence or rare appearance of a spark. The presence of defects in the sparking system can be easily detected if the car engine starts to jerk when descending from hills and even on flat sections of the road.

For example, a problem with a set of candles is typical for Nissan vehicles. This is due to the equipment of their CA-18 model engine with a special design of a non-contact distributor. The distributor housing contains a switch, in the event of a malfunction of which the spark signal is not sent to the on-board computer, and such a specific movement of the machine occurs. You can fix the jerks of the motor only with a complete replacement of the components of the distributor.

If the set of candles is also in excellent condition, the only remaining reason can only be malfunctions in the operation of the carburetor-type engine control unit. In this case, jerks do not occur constantly, but randomly and only during a long drive of the car.

It is possible to detect malfunctions in the control unit only after diagnostics in a car service on a special stand. Also, with the help of a lift, you will be able to see that the car idling occasionally twitches. As a result, the control unit (EFI) should be changed along with breakdowns found in other components of the vehicle.

car pads

Video: the car twitches while driving - several reasons

The most common problem that car owners may encounter is the sudden "jerking" of the car in different situations. For example, during acceleration, at low speed or at the very beginning of the movement. Those who have been driving for more than a dozen years do not focus on this at all. This is explained by the fact that these “symptoms” can be expressed in any car, and it doesn’t matter how old it is, what brand it is, how much experience its driver has.

Lada Desyatka, Hyundai Solaris, and any other car can "rush" from a place. But this is, in any case, a deviation from the norm of the engine. Therefore, at the first unpleasant situations, it is necessary to identify the cause and get rid of the problem. Because the longer you ignore this kind of movement, the more the entire repair will cost you.

A twitching car is not the most desirable road user. In which case, you will definitely collect a couple of accidents in your piggy bank. Photo: desertoasisautorepair.com

By the way, you should not try to solve the problem on your own if you are not confident in your skills and abilities. Entrust the car to a knowledgeable and experienced workshop technician. Do it as soon as possible.

Why the car may start to twitch

So, if your car began to make “tearing” movements that were not characteristic of it and did not appear before, you should do:

Remember candles. Check their performance. Replace if necessary.
Check the wiring of the car, and in particular the ignition coil.
Check the injectors, they may be clogged and cause twitching.
Don't forget air and fuel filters.
If you have a carburetor, check the ignition timing
Check fuel pump. Perhaps because of it, gasoline is supplied unevenly
Check fuel pressure. Maybe it's just not enough power.

Possible causes, depending on the type of car engine, and their elimination will be discussed below.

If you have an injector

Jerking movements are common, especially if your car is more than three years old, and during this period it was actively exploited. Photo: 111.ural2.ru

The problem arises because when the engine is still cold or just starting to warm up, there is a sudden “drop” in speed, and the difference between the deviation and the norm is a fraction of a second. The number of revolutions varies from five hundred to one and a half thousand. Further, as the engine warms up more, the number of revolutions is normalized, dips and drops disappear and do not repeat until the next time, when the engine cools down again, and it will be put into action again. Such "tricks" can discourage even the most experienced motorist. And the reason for this action is just a sensor. Yes, temperature sensor.

How to solve this problem? Elementary: buying a new one and replacing the old one.

On the injector, such problems can also occur due to the fact that an electronic fuel injection system is installed on the engine. And the reason lies in the wrong flow of air. It all starts with the fact that the control unit incorrectly calculates the required amount of air to enter. Air enters the cylinders, the injector valves open. And there is more air than necessary! Consequently, the throttle sensor is triggered, along with it the temperature sensor shows that the engine has already warmed up, and less gasoline needs to be spent. The computer has a "shock", he does not understand what to do with this very excess air.

If, with a sharp press on the gas pedal, the car pulls forward, then the problem lies in clogged injector nozzles. It is treated by washing them out with a special agent under high pressure, or by ultrasound.

Also, the problem may lurk in the ignition system. Look for faults either in the wiring, or in the candles, or in the ignition coil. In any case, you will have to replace the non-working element.
Another cause could be a stuck crankcase ventilation valve.

If you have a carburetor

The jerking of the carburetor machine without any suspicious and incomprehensible sounds and rattles may indicate a malfunction or malfunction of the carburetor or ignition system itself.

In most cases, cars with this type of engine twitch precisely because of its clogging. Photo: cdn.klimg.com

What to do in this case? In no case do not self-will and do not self-made! Contact the master. He will clean the carburetor channels, the idling system, jets. Also, the specialist will properly check the carburetor, if there are any mechanical damage that may be the cause of jerky movements of the car, he will quickly fix them. One of these damages is the sticking of the throttle valve of the carburetor mixing chamber. In view of this, the engine cannot gain the power it needs and the car just simply starts to pull.

Don't forget the fuel filter. If it was replaced a long time ago or never at all, then the car jerks at low speeds due to the fact that little or practically no gasoline enters the fuel supply system at all.

There are other options for causes related to gasoline. For instance, bad pump pumping gasoline. Because of this, the car “lives its own life”: it stalls, accelerates hard, twitches when switching gears. The solution to the problem is elementary: blow it out of dirt or replace it with a new one.

If the car jerks when accelerating, pay attention to this video:

If you have a diesel

With a diesel engine, everything is very clear. Firstly, such cars will twitch only at idle. Secondly, there is only one reason for jerks - stuck movable blades in the feed pump. And this happens because of a common disease of cars - rust. Only this rust is formed due to water that got along with the fuel. Where did she come from? From the street! Perhaps the car faithfully defended the rainy autumn and snowy winter on the street under the open sky. It is for this reason that cars are recommended to be put in garages for the winter or, at least, under sheds.

But, if this is not possible, and the diesel car still has to stand on the street, special additives must be poured into the fuel. And auto mechanics from the northern regions recommend pouring a little special motor oil into the fuel tank.

Outcome

Even the most careful and thrifty driver is not immune from a car breakdown. This is influenced by many factors beyond the control of the driver. Build quality, reliability of installed parts, correct calculations of engineers, road conditions, duration and intensity of operation, and even climatic conditions. But every car owner must maintain the working condition of the car. And if you stubbornly ignore his "complaints" and continue to ride, then you can finally "kill" him.

Of course, it will be possible to try to “reanimate” it, but this can cost a fairly tidy sum. Moreover, the reasons why the car can twitch lie on the surface. Candles, clutch, filters - small details leading to big problems. Take the time and some money to take your car in for diagnostics.

She needs it regularly, like a visit to the hospital. For proper care, the car will thank you for many years of faithful service!

Sooner or later, every motorist has to deal with the following problems:

The appearance of malfunctions in the operation of valves;
Sharp jerks of the car (there is a feeling that it is twitching by itself);
The lack of an instant response of the motor to pressing the gas pedal.

The main reason for the "jerking" of the car when you press the gas pedal

Jerking of the car due to a malfunction of the TPS

Jerking the car - a malfunction in the carburetor chamber and pump

A classic example is the following situation: when the pump is damaged. As a result of the failure of the accelerator pump of the carburetor, the mixture is supplied to the engine in an incomplete volume. The result is the appearance of jerks during even a smooth attempt to start. In most cases, it is not advisable to repair pumps, which is why they are simply changed in a car service.

carburetor chamber

Vehicle jerking during acceleration

The solution to a fuel pump malfunction takes place in 3 stages:

Remove the top cover of the pump and carefully inspect the surface of the hole where the valve structure should be located;
If the sealing ring is worn or missing, fix a new one;
If during the diagnostics a depressurization of the chamber is detected or the problem is related to interruptions in fuel injection, then the final stage will be associated with the complete replacement of the inoperative valve and the further restoration of the tight state in the system.

Advice: when repairing, do not try to repair holes in the old cylinder and install it in place. In the future, this can lead to a major overhaul of the entire engine structure.

fuel mixture

The appearance of jerks in the car when you sharply press the gas

If the oxygen supply sensor does not work properly, the system is diagnosed using a multimeter. In the event of a malfunction, it is simply replaced.
When the valve timing is shifted in the motor, it is necessary with the help of car service specialists to adjust them according to the appropriate instructions.
The detection of an incorrect glow number of candles is solved by installing a new kit with the correct number.
The problem of nozzle clogging can only be solved in a car service. To do this, they are installed on a special stand that simulates the operation of the motor, and washed with a special solvent.
Also, a problem may arise when the emulsion tube and well located in the design of the second chamber of the carburetor motor are clogged. The only solution here is to flush the carburetor and tube with kerosene.

Engine jerks due to problems with the ignition system

The tightness of the fastening of the pads with wires is checked;
No chips and good condition of the coil;
The serviceability of the wiring connecting the ignition system to the engine.

Advice: do not attempt to change the wiring on the machine yourself. Only highly qualified specialists can correctly connect relays and fuses using instructions and diagrams, after which the ignition system will not burn out. You can also check the wheels at the same time by checking the indicators in.

car pads

Video: the car twitches while driving - several reasons

Many owners of cars, both domestic and foreign, often face the problem of car jerks when the gas pedal is pressed. There are many reasons for this behavior. Therefore, we suggest that you further familiarize yourself with the most common malfunctions that cause such jerks, as well as their symptoms and solutions.

1 Malfunction of fuel system sensors

A common cause of jerks when the gas pedal is pressed is a malfunction of the TPS, especially this often happens with "VAZ" models. This sensor detects the throttle position. It is quite simple to identify its malfunction, thanks to a characteristic symptom - the car starts to “jump” during acceleration, even if the gas pedal is pressed very smoothly.

Most often, as a result of a TPS malfunction, the throttle valve remains in an ajar position for a long time. When you press the gas pedal, the sensor does not immediately transmit a signal to the computer. As a result, the engine at first cannot change the mode of operation, and then the fuel is supplied abruptly and in large volumes. As a result, the engine begins to “choke” and work jerkily, and sometimes it stalls altogether.

There is only one way to solve the problem - change the sensor. True, some car services offer controller repair. But, as practice shows, a repaired TPS serves no more than one or two months. Therefore, it is better to immediately buy a new part. In the photo above you see the location of the TPS in a VAZ 2114 car.

Another sensor that, when it fails, causes the car to twitch is the air flow sensor (DMRV). In the event of a breakdown, the engine starts to work unstably at any pressure on the gas. As in the previous case, the problem is solved by replacing the sensor. Sometimes the problem is not the sensor itself, but the air duct (corrugation) that goes from the air filter to the engine. As a result of its depressurization, air leakage can be carried out bypassing the sensor, which causes malfunctions in its operation.

For some cars, jerking when picking up speed at idle can occur as a result of a failure of the crankshaft position sensor (DPKV), which is located near the oil pump. The photo below shows the location of the DPKV of a Priora car with an engine of 21126, i.e. having 16 valves.

To check the operation of this controller, you need to connect an oscilloscope to it. Smeared or barely noticeable pulses indicate that the sensor is really not working correctly. Please note that if it is completely out of order, the car generally stops starting.

2 Problems in the fuel supply system

Often the car starts to twitch when starting off and picking up speed as a result of a lack of fuel in the float chamber. Most often, the malfunction manifests itself when you sharply press the gas. This is due to the fact that the fuel is burned in the engine much faster than it enters the float chamber.

There are several reasons why this situation may arise. Typically, fuel interruptions occur as a result of a malfunctioning fuel pump. To resolve this issue, you can follow these steps:

Remove the pump cover.
Examine the surface of the lid. Replace sealing ring if necessary.
If chamber depressurization or other fuel injection problems are found, worn parts must be replaced.

Most often, the fuel pump is located under the hood. However, some vehicles may have it at the rear. For example, in the VAZ 2110 and VAZ 2112 models, to access the fuel pump, you need to dismantle the rear seat and unscrew the cover, as shown in the photo below.

Sometimes the cause of all problems in the fuel supply system is banal - the fuel filter is clogged. If it is not replaced in time, it can become so clogged that the fuel supply stops altogether and it will be impossible to start the car.

3 Malfunction in the mixture preparation unit

If the car is dull when picking up speed and starts to twitch when the gas pedal is pressed sharply, it is quite possible that the malfunction lies in the mixture preparation unit, i.e. carburetor or injector. Most often this occurs as a result of clogged jets, air channels or nozzles. Car owners usually face a similar situation in the spring, after a long idle time of the car or after filling low-quality fuel.

In some carbureted cars, for example, the VAZ 2109, you can correct the situation without even removing the carburetor. To do this, you just need to dismantle the air filter located above the carburetor, and then blow through all the channels with a hand pump with a cone tip. It is advisable to do the work together, so that one person puts the tip to the channels and holds it, and the second one works with the pump with sharp and powerful movements.

Of course, such manipulations will not give a 100% result, and besides, the situation will improve for a short time. But if the problem happened on the road, purging with a pump can really help out. For normal cleaning, you must contact the service center, where specialists will wash the carburetor with a special tool. The situation is exactly the same with the injector: blockages can only be eliminated by flushing. Moreover, for this it is necessary to use a special tool for injectors.

It must be carried out on a special stand that simulates the operation of the engine, so it is impossible to do it yourself.

4 We are looking for a reason in the electrician

Very often, the cause of the car jerking and slow revving is the “trimming” of the engine due to a malfunction in the ignition system. In this case, when you gently press the gas pedal, the problem is often not noticeable at all, but when you press it hard, the engine seems to "choke". At high speeds, "trimming" may also not be felt. In motion, jerks can occur only at certain speeds or when the car is moving up a hill.

Most often, in such a situation, replacing candles helps. However, the problem is not always in candles. Often, "trimming" occurs due to problems with high-voltage wires that go from the distributor to the candles. You can identify a faulty wire by simply listening to the wiring with the engine running. A wire that has a "breakdown" makes a characteristic clicking sound. In the dark, you can even see a spark. True, in some cases, the wires fail asymptomatically, therefore, it is possible to identify a faulty element only by replacing the wires one by one.

Sometimes it’s not even the wires themselves that cause the problem, but the tips on the coils and candles. Accordingly, it is easily solved by replacing the tips.

That's all the common reasons why the car starts to twitch when you sharply or even smoothly press the gas pedal with your foot. If, after performing all the above steps, you could not fix the problem, contact the service center, where specialists will perform computer diagnostics and accurately determine the cause of the malfunction. It is often possible to get rid of jerks only after flashing the on-board computer.

The jerking of the car during acceleration can be caused by various reasons. In most cases, to identify this phenomenon, it is enough to simply check and listen to the operation of certain machine components. However, regardless of the reasons for this “behavior” of the car, it is necessary to fix the malfunction as quickly as possible, otherwise there is a possibility of more serious problems.

Dips and jerks on the carburetor engine

If the car twitches during acceleration and further revs, and there are dips when you press the "gas" pedal, it is first of all recommended:

Check or replace air and fuel filters. If they are heavily contaminated, the supply of air and fuel is complicated, which can lead to jerks.
Unstable flow of fuel into the float chamber, which is usually associated with problems in the operation of the fuel pump. Its replacement allows you to solve the problem with the jerks of the machine.
Fuel supply under insufficient pressure. Checking the fuel pressure is carried out by connecting a pressure gauge to the fitting on the fuel line (a piece of hose is used for this). With the engine running, the pressure in the fuel line should not exceed 3 kgf/cm2.

If the pressure does not correspond to this indicator, then the cause of the defect must be sought in the following vehicle components: fuel pressure regulator, fuel filter or fuel pump.

The causes of “failures” (when you press the gas pedal, the car refuses to accelerate) and the jerks that accompany this are often:

The ignition coil, together with high-voltage wires, which, due to long-term operation and wear, begin to “break through”, as a result of which the engine begins to triple. The solution to the problem is to replace the wires and coils.
Spark plug. They cause jerks of the car as a result of the appearance of strong soot on them and poor contact with the wires.

Checking high voltage wires

To check the condition of the high-voltage wire, it is necessary to remove its tip, suitable for the spark plug. Inside the winding there is a central core, which should fit as closely as possible to the so-called. a metal penny placed in the tip of the wire.

This nickel is designed to transmit current to the spark plug, and if there is no contact between the wire and the nickel, then the current may not flow, resulting in tripling. The main reason for the “failure” of the wire is its oxidation.

Checking for the fact of oxidation of the wire is carried out using the second probe of the multimeter, which must be touched to the central core of the high-voltage wire. If burnout is observed along the entire length, then the damaged area is determined by piercing the wire every 5-10 mm using a special multimeter tip. The damaged section, if the length of the wire allows it, is simply cut off, in other cases, the entire high-voltage wire is changed.

Causes of jerks on injection engines

Injection engines, compared to carburetor options, have better technical and operational characteristics. However, they also have a more complex design, so there can be much more reasons that cause car jerks during acceleration than for cars equipped with carburetors.

A feature of the injector is the presence of an electronic control unit for the fuel supply system, which is regulated using various sensors. Vehicle jerks predominantly cause problems with the following sensors:

Mass air flow sensor.
Throttle position sensor.
Crankshaft position sensor (DPKV) - problems with this sensor are considered the most “unpleasant”, since its failure leads to the injector stopping, respectively, the ability to start the car is completely excluded.

The DPKV is checked by connecting an automotive oscilloscope to it. If the sensor is working, then clear pulses of the injector will be displayed on the screen of the device. In the absence of pulses or their blurring, it is necessary to promptly replace/repair the sensor. It is also desirable to perform an additional check on the operation of other controllers, which may allow you to determine the malfunction of the oxygen sensor or, for example, the electric injector valve, which can also lead to car jerking.

The causes of jerks in injection machines, as for carburetor vehicles, can be problems in the ignition system (plugs, ignition coil, high-voltage wires), as well as fuel system malfunctions (clogged fuel injectors and filter).

Another common cause of car jerks is the use of low-quality fuel. Such fuel leads to the formation of a lean mixture, the characteristics of which are not enough for stable and high-quality engine operation.

In most cases, it is possible to eliminate the problem of car jerking during acceleration quite quickly, the main thing is to start repair work in a timely manner and prevent more serious malfunctions.