Why does the car jerk when driving at low speeds?

Manifestation of the problem

As a rule, if the car jerks, this is usually due to various circumstances. Every driver should understand that any non-standard situations do not appear out of nowhere; this may be due to a malfunction of a particular system. In turn, this is usually due to wear and tear on vehicle components. And if you lose sight of this, sooner or later, it can result in serious and costly repairs.

As for when the problem begins to manifest itself, vehicle jerking can be noticed in the following cases:

Only when the car starts moving.
When the engine is running at low speed.
During a sharp increase in speed.
When the car is moving at high crankshaft speeds.
In any mode of vehicle movement, which is manifested by periodic jolts at different times.

But what exactly can cause a vehicle to behave this way? When a VAZ-2114 jerks while driving, there may be several reasons for this, and quite a few. In fact, this is what we will discuss further.

The accelerator also cannot be discounted

At the moment when the driver sharply presses the accelerator pedal, there is a rapid increase in crankshaft revolutions. However, this may cause the vacuum ignition angle regulators to malfunction. Ultimately, the distributor lags at low speeds, and the car begins to jerk.

As the crankshaft speed increases, the engine needs to work faster, igniting and admitting the fuel-air mixture. However, if there are problems with the vacuum regulators, there may be problems with opening the throttle valve and it will not be possible to quickly increase the speed. As a result, gasoline burns at the wrong time, which can damage the bearing responsible for the ignition timing.

To confirm or refute the problem when the VAZ-2114 jerks while driving, it is worth checking the vacuum regulators. Diagnostics is done like this: before starting the engine, you should remove all the pipes with hoses, first covering them with your hands. While the engine is running, you can hear the retractor effect of the regulators.

However, if a vacuum does not form during the working mixture, then the cause of the leakage lies precisely in the damper. The element needs to be replaced.

The engine jerks at idle: the main reasons

The idle mode involves the operation of the internal combustion engine at the lowest speeds, when the gas pedal is not pressed and air is supplied to the cylinders bypassing the throttle valve. As a rule, in idle mode, the power unit does not transmit torque to the wheels of the car, since this mode is activated when the car is parked with the engine running, when coasting in neutral gear, as well as when the clutch is depressed to change gear, etc. .d.

Moreover, it is typical for such a problem that when the speed increases or after the engine begins to load, the symptoms disappear. Otherwise, the engine twitching disappears after the internal combustion engine switches to another operating mode. Next, we'll talk about why the engine jerks at idle, as well as how to detect and fix the problem.

"Personal" motives

The cases listed above are the main reasons why the steering wheel twitches when driving a VAZ-2114. Moreover, this is observed when starting or accelerating. However, it should be taken into account that each vehicle has individual characteristics, which are comparable to the human body.

In other words, each car has its own “diseases” and the appearance of the “symptom” in question is precisely due to the presence of design flaws.

Sooner or later, every car enthusiast encounters this phenomenon: the engine suddenly starts running jerkily, the car seems to twitch. This can happen at any time. When accelerating, sharply pressing the gas pedal and even at idle. We will talk about why this happens and how to deal with it in this article.

Unstable engine operation

Unstable engine operation when cold can create discomfort, which many people fix for money at a car service center. But, this malfunction can be fixed in your garage, with a minimum set of tools.

This engine trembles when starting

Of course, novice motorists first need to study the structure of the VAZ-2114 engine.

Main reasons

So, first we need to consider what could be the reasons why the engine started to misfire when cold:

Problems with spark plugs.
Malfunction of high-voltage wires.
Malfunction of the mass air flow sensor (see “checking the mass air flow sensor on the VAZ-2114”).
Fuel system malfunction.
Valve clearances.
Air filter.
ECU.

Elimination methods

Now that the main causes have been identified, you can proceed directly to identifying the specific cause and the elimination method that will lead to normalization of the operation of the main power unit. So, let's consider the sequence of actions aimed at eliminating the causes of the effect.

Spark plug

Dirty spark plugs

The first and, perhaps, the most common reason that the engine begins to stall was and remains spark plugs (see “choosing spark plugs for the VAZ-2114”).

Accumulated carbon deposits or breakdown of an element may cause the fuel mixture to stop igniting in one of the cylinders. To fix the problem, you need to carry out a number of operations:

Remove the terminal from the battery.
We remove the high-voltage wires from the spark plugs.
Using a spark plug wrench, we remove the spark plug sequentially from each cylinder.
We carry out diagnostics, namely inspecting the element, as well as measuring gaps and resistance.

When a non-working spark plug is found, it must be replaced with a new one, having previously adjusted the gaps, and also checked for resistance. This is due to the fact that even from the manufacturer’s factory you can receive a defective part . Now, we install a new element and put everything back to its original form. Next, you need to check whether the negative effect has disappeared.

High voltage wires

High voltage wires are marked with arrows

High-voltage wires are another common cause of unstable engine operation. Moreover, this effect will be visible not only when cold, but also at speed. Diagnostic operations are carried out quite easily:

We remove the wires from the spark plugs and ignition coils.
We take measurements using a tester or an oscilloscope (if available).

If the measurement shows that one of the wires has failed, or there is a visual violation of the insulation, it must be replaced with a new one.

As practice shows and the manufacturer recommends, it is best to replace high-voltage wires as a set so that the engine can operate without any changes.

Air filter

Part of the air filter replacement process

If the problem is not in the ignition, then you need to pay attention, first of all, to the air filter. Clogging of this element can lead to the engine stopping “breathing”, namely, the supply of the necessary air mixture to the main power unit is limited. This malfunction may affect operation when the engine is cold. To eliminate the problem, you need to replace the air filter.

Valve clearances

Valve clearance adjustment process

Every 20,000 km, it is necessary to adjust the valve clearances, and if the motorist does not do this on time, this can affect the operation of the engine not only when it is cold, but also when the dynamics gain, which will drop.

So, it is worth checking the clearances on the valve mechanism and adjusting if necessary.

It is recommended not only to set the required clearance on each valve, but also to dismantle the cylinder head, and also check the condition of the valves, camshaft and combustion chamber cylinders. It is in these places that the problem may lie.

DMVR

A malfunction of the mass air flow sensor can cause unstable engine operation when cold.

Another common malfunction that directly affects the stable operation of a cold engine is the mass air flow sensor. Checking this electrical element is quite simple, as is replacing it. Therefore, every motorist will be able to do this without much effort and problems.

Fuel system

Fuel system diagram

The fuel system directly affects the stable operation of the engine in any mode. So, all this may be due to the fact that an unbalanced air-fuel mixture can not only disrupt the performance of the main power unit, but also lead to other consequences. Let's look at what elements of the fuel system you should pay attention to when looking for the cause:

The fuel pump may not pump fuel into the fuel rail efficiently enough.
A malfunction of one of the injectors can lead to the engine not only running rough, but also having difficulty starting. In this case, this may lead to the motor not starting to work at all. Also, a faulty injector will lead to the fact that one cylinder may flood, which will “throw” the spark plug and prevent it from working (see “replacing injectors on a VAZ-2114”).
The fuel pump and rail can indirectly affect the performance of a cold engine.

ECU

Location of the ECU in the cabin

Now, let's look at the last reason why the effect of three cylinders working may occur. Errors in the electronic engine control unit can also cause the “brains” to issue incorrect commands or not completely.

This malfunction can be cured quite simply; you need to connect to the control unit and read the necessary data. Next, you should reset all accumulated errors. If these operations do not help, then you should flash the control unit.

Mix preparation unit

Depending on the type of engine, the injector or carburetor is responsible for preparing the mixture. Mechanisms can cause jerking when driving. In the injector, the malfunction is caused by clogged air channels or nozzles, in the carburetor - by the jets.

The units become clogged after refueling with low-quality fuel, when the car has been standing idle for a long time.

To fix the problem, cleaning is required. In the case of a carburetor, you can do the procedure yourself even on the road. Under the hood you need to remove the air filter to gain access to the carburetor. It is necessary to blow out the channels with a pump. It is more convenient to use a compressor; a regular hand or foot compressor will do.

The effect of the procedure does not last long; in emergency cases, this is the only option to get to a service station. It is recommended to completely flush the carburetor with appropriate products. If you have no experience in carrying out such actions, it is better to trust the professionals in the car service.

In the case of an injector, you won’t be able to flush the system yourself; to do this, you need to imitate the operation of the engine, and special equipment is required. You'll have to go to a car service center.

Many people wash the injectors, and the problem goes away for some period. This effect will not last long, the parts will become clogged with dirt again. You need to purchase new injectors and install them to replace the old ones.

Idle speed sensor

When the driver feels his vehicle begin to jerk, it makes sense to check the condition of the idle speed sensor. At the same time, such a malfunction is very difficult to identify, since often the well-known Check Engine indicator simply does not appear on the dashboard.

For this reason, it is worth checking it first. In this case, the nature of the malfunction may be different. Firstly, the sensor is contaminated with oil, dust, and crankcase gases. Secondly, you should not discount the mechanical nature of the damage - the rod, threaded connections, rivets flying out and other cases. Thirdly, this is a failure of the electrical part.

Electronics

The car may jerk when you step on the gas due to electrical faults. The problem is in the sensors and spark plugs. You need to check other elements as well.

Rarely is the generator causing the jerking. When diagnosing, the node must be tested. If the mains voltage is low, the generator operates intermittently, some parts in the device are worn out. The fuel pump and ignition system will not be able to function normally, even if the mechanisms are working properly.

When a car is equipped with a mechanical distributor, the problem may be hiding there. At high humidity, condensation forms, which falls on the contact groups and into the housing of electronic units. The spark occurs in the distributor, this should not happen.

The problem is the formation of condensation. It is necessary to leave the car in a dry room and check how the engine will work. Condensation is preliminarily removed.

Supply system

As a rule, the main reason that the VAZ-2114 car jerks when driving is due to a malfunction of the power system.

Usually, experienced car enthusiasts and auto mechanics try to look for the cause here first, and they will be right. While the vehicle is starting to move, insufficient fuel may be supplied to the cylinders. This leads to the development of low power, which is not enough for full operation of the transmission.

In other words, if there is an uneven supply of the fuel-air mixture in the power unit, then it will simply not ignite well. In turn, because of this, the timing of the explosion is disrupted, and the heart of the car begins to malfunction. The driver feels this, which causes a lot of discomfort while driving. What can be done:

Check the functionality of the hall sensor.
Pay attention to the position of the throttle valve.
The condition of the injectors also deserves attention.

In addition, to understand the reason why the VAZ-2114 injector twitches when driving, it is necessary to evaluate the condition of each element of the fuel system. Moreover, regardless of the type of power unit. As experts note, due to depressurization of the pipes, the engine experiences fuel starvation. This is manifested by failures in engine operation. Therefore, it is better not to neglect a thorough check of the pipes!

Fuel pump

Without a stable fuel supply, normal engine operation is impossible. To ensure the engine starts, two factors are sufficient - the presence of a spark and fuel. The fuel pump is responsible for supplying gasoline. In model 2114 cars it is located under the rear seat and mounted directly into the tank.

There may be several reasons why the fuel pump failed:

Clogged strainer on the fuel pump. In addition to the main fuel filter under the car tank, the pump design includes a mesh to filter fuel from debris. Over time, it becomes clogged, which is why the fuel does not flow in full;
There is damage in the wiring or the fuel pump is turned off due to a loose connector. The problem can be solved by cleaning the contacts and checking the connection of the chips;
Overheating of the electric pump is another cause of the stalling engine problem. It may overheat due to short-term and often repeated contact failures in the power supply circuits.

When looking for an answer to the question “VAZ 2114 starts and immediately stalls - what is the reason?”, the fuel pump should be checked first.

Maybe it's all about the checkpoint?

Another version of why the VAZ-2114 twitches while driving affects the transmission mechanism. As a rule, this behavior of the car can be caused by improper operation of the engine and lack of regular maintenance of automatic transmissions. With the total mileage of the car from 100 to 200 thousand km, you should not be surprised at its jerks.

Moreover, even if the box looks good on the outside, it doesn’t mean anything. This is mainly due to excess and lack of transmission oil - it will begin to foam, which leads to twitching.

It is worth paying attention to the following elements:

Are the fastenings loose or is there damage to the drive cable?
The shift rod may be damaged.
The locking device is worn out or deformed.
The gear fork is worn out.

It is these elements that are responsible for starting the car to move. Therefore, when a VAZ-2114 car jerks, they are also checked first. Fortunately, repair work on the box does not take too long. In a car service center, they will remove and restore the mechanism in almost a couple of hours.

Throttle valve

The cause of the breakdown is contamination of the throttle valve. The car's response to the gas pedal is late, the speed is uneven, the engine stalls, the part needs to be washed. Necessary:

Buy a special product at a car store.
Remove the damper.
Rinse thoroughly.
Install back.

If these steps do not help, the problem is related to the power supply (see below).

On foreign-made cars, the throttle damper could fail. Then, when you release the gas, the engine will stall. The part is responsible for returning the damper to its normal position, eliminating dips.

To check the damper you need:

Warm up the engine to operating temperature.
Open the valve yourself.
Let go quickly.

The part should return almost to the limit, pause and not reach the end so quickly. If no deceleration is observed, the damper is faulty. It needs to be replaced, repair is impossible.

Air filter?

As is known, the formation of an engine working mixture requires a certain amount of air in which oxygen is present. And without it, the combustion process itself is impossible. In a car, before entering the working chamber, the air passes through the labyrinths of the filter and only after that it combines with the fuel mixture, forming just the working composition.

However, if this element is contaminated, the car may also begin to jerk while driving or when starting off. As a result, the flow decreases significantly and there is simply no longer enough air in the required quantity. This risks the working mixture becoming rich in fuel and burning incorrectly.

As a result of this, the VAZ-2114 jerks when driving, and in some cases there may be misfires.

Diagnostic features

It is worth considering that there are no exact sequential actions by performing which it will be possible to accurately determine the cause of the malfunction. If the power unit stalls only occasionally, then the situation may not be that serious. There is a chance that this is how the vehicle simply reacts to severe frosts. However, if you have recurring problems, you should contact a specialist.

It is best if the mechanic connects a specialized diagnostic device to the car at a car service center. He will determine exactly where the breakdown occurred and which element should be replaced. Of course, if the car owner has enough knowledge, he can identify the problem on his own. But you need to understand that if such a diagnosis was performed incorrectly, this can lead to more serious consequences. In this case, the final repair of the car will be much more expensive. Therefore, you should think several times before saving.

The “fourteenth” model from the domestic automaker AvtoVAZ gained enormous popularity in its time due to its reliability, workmanship, responsiveness and agility of the power unit.

Of course, this car cannot be called ideal. Therefore, problems may arise from time to time. It is not uncommon for the rpm to fluctuate at idle. Such phenomena irritate the driver and lead to unpleasant scenarios on the road. For example, at any moment the engine may simply stall.

It is unlikely that you will be able to solve the problem for a long time by pressing the accelerator pedal in order to maintain speed. Therefore, more drastic actions need to be taken.