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.

"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.

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.

Useful tips

Quite often, engine jerking at idle can occur precisely when the internal combustion engine is cold. In this case, you should pay special attention to the motor temperature sensor.

Failure or malfunctions in its operation often lead to the ECU receiving a premature signal to warm up the power unit, while the engine is still cold.

A similar situation can occur when air leaks appear or problems arise with the air flow sensor (MAF). In this case, the control unit incorrectly calculates the actual amount of air that enters the cylinders, as a result of which the correct ratio of fuel and air will be disrupted (disturbance of mixture formation).

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.

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.

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.

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!

What causes the car to jerk when running at low speeds?

Since the car begins to twitch when reaching even low speeds, it will not be possible to immediately identify one specific problem. Problems may be hidden:

In the engine fuel mixture supply system;
In the vehicle ignition system;
At the checkpoint;
In the distributor design;
Includes fuel filters;
In the sparking system;
In the control unit of the vehicle's on-board computer.

Let's go through the faults in each of the listed systems in detail.

Tip: When detecting a “jerking” behavior in the vehicle, the brakes may also squeak when braking. These 2 problems can be either interrelated or indicate completely different breakdowns.

Checking the engine fuel mixture supply system

Often the reason that the car jerks at low speeds is due to a malfunction of the power system. When the car starts to move, the cylinders simply cannot receive the required amount of fuel mixture, as a result of which the car is unable to transfer the required amount of power to the chassis for smooth driving and smooth commissioning of the transmission. As a result of increased pressure and transmission resistance, uneven running of the machine appears.

To solve this problem, it is recommended that you first pay attention to checking the throttle body. It also wouldn’t hurt to test and diagnose the performance of the sensors installed in the system for determining idle speed indicators. Do not forget to check the serviceability of the throttle valve position and the mass air flow sensor.

Throttle body

During diagnostics, most often a breakdown is found in the injectors responsible for uniform injection of the fuel mixture. In rare cases, engine jerking problems may be related to the air ducts that connect the injector receiver to the air filter structure. Here the problem lies in depressurization of connections and loss of pressure.

The solution to the problem is to replace all faulty components yourself or with the help of car service specialists. After repair, it is recommended to ensure that all connections are in good working order and that there is no loss of pressure in the fuel line system that is connected to the fuel pump itself.

If a power unit with a carburetor system was installed in the engine compartment of your vehicle, then you need to check the idle valve and the absence of damage directly to the carburetor.

Checking the car's ignition system

Sometimes the car starts to jerk while driving at low speeds as a result of a breakdown in the ignition system. Basically, the problem will be caused due to untimely ignition of the fuel mixture and air flow. In rare cases, the malfunction may be hidden in the receipt of low voltage from the spark plugs. The spark voltage simply will not be enough to ignite the fuel mixture in a timely manner. Also, when diagnosing the ignition system, check:

Performance of ignition coils;
Serviceability of the spark plug set;
No tears in high-voltage wires;
There are no problems in the ignition distributor-interruptor (in simple terms - in the distributor);
Correctness of values coming from a set of sensors responsible for the position of the camshaft and crankshaft;
The performance of the switch located inside the entire structure.

Often, the car may jerk due to the long use of a set of spark plugs. There is often a situation where problems are caused by spark plug gaps not meeting established standards.

Advice: if the ignition module on a VAZ-2112 is faulty, the crankshaft position sensor will be damaged and it will not be possible to start the car’s engine at all. This problem can only be solved after a thorough check and subsequent repair of the knock sensor.

Checking the car gearbox

Jerking of a vehicle engine often occurs due to improper operation of the engine and infrequent maintenance of automatic transmissions. If the total mileage of your car is 100-200 thousand km, then even with a seemingly serviceable gearbox, the car will move with some jerks.

As a result of frequent jerking of the engine, the oil in the box foams, causing the amount of solution to be either too small or too large. Repairing a gearbox takes a little time. In a car service center, in just a couple of hours they will remove the box and restore its operation.

Problems with the accelerator

At the moment when the driver sharply presses the gas pedal, a rapid increase in engine speed occurs, which, in turn, can lead to ineffective operation of the vacuum ignition angle regulators. As a result, at low speeds the distributor will sink, and the car will begin to move jerkily.

Since, with the gradual combustion of gasoline, the driver begins to increase engine speed, the engine must ignite and let in the fuel and air mixture even faster. If there is a problem with the vacuum regulators, the car will not be able to quickly increase speed, which will cause problems with opening the throttle valve. Without the simultaneous opening of the damper and air supply, gasoline will not be able to burn in time, which can ultimately lead to damage to the bearing, which is responsible for the ignition timing.

To solve the problem, the vacuum regulators are first diagnosed. Here you can independently remove all the hose and pipes, having previously tightly covered them with your hands. When the engine is running, you will hear the retracting effect of the regulators working. If a vacuum does not form when the air mixture is supplied, it means that the seal is broken precisely because of the damper. You should replace it and assemble all components in the reverse order.

In the life of every car enthusiast, different situations may arise, regardless of the vehicle manufacturer. Both owners of foreign cars and lovers of domestic AvtoVAZ products can face various troubles. For example, for no reason at all, a VAZ-2114 jerks when driving, and this situation can be repeated more than once during the year. As a rule, this problem is solved in a short time.

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.

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.

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.

Cleaning the throttle body

First you need to disconnect the clamps that secure the hoses going to the remote control. You will also need to remove the pads from several sensors, or rather, the IAC (if any) and the TPS. After this you need:

Remove the accelerator cable.
Remove the throttle assembly itself and assess its condition visually. Such self-diagnosis will help you understand whether the VAZ 2114 injector really stalls at idle due to remote control.
Disconnect the IAC, which is located inside the throttle.
Assess whether there is accumulated carbon deposits under the sensor. If it is not in the chamber itself, this does not mean that it is also clean under the regulator. As a rule, all cars with decent mileage accumulate a lot of carbon deposits.
Clean the IAC needle using a specialized aerosol. You need to process all parts very carefully, and then wipe them dry with a clean cloth. You must act with extreme caution so as not to damage anything. Therefore, it is better if you have a compressor at hand.

If the Lada Samara has low mileage or the sensor has recently been cleaned, then problems may lie in other parts.