Malfunctions and irregularities in engine operation can manifest themselves in different ways, starting with suspicious sounds coming from under the hood, leaks that remain on the asphalt after a long stay, and ending with jerks while driving.
Jerks while driving can occur regardless of how you press on the gas pedal, this occurs as a result of a short-term change in the speed of rotation crankshaft... Dips can occur not only during acceleration, but also when throttle is released, as well as with constant movement and the same position of the gas pedal. To understand why does the car jerk when driving the best and easiest way is to contact the specialists at the service station, because, most likely, you will have to produce injection systems, and for this, as you understand, you need to have special equipment. In most cases, jerking during driving occurs due to a violation of the pressure in the fuel rail, or as a result of a malfunction of the position sensor throttle(TPS).
The car twitches while driving - reasons
Sometimes during the beginning of the movement, when you start off, there is a "failure", while quite often for beginners because of this, the engine can even stall. This effect occurs exactly at the moment when the throttle valve opens, when the engine changes from idle speed into load mode. V modern engines The motor helps the driver, for the smoothness of the ECU, having received a signal from the TPS about the throttle position will increase the fuel supply. However, if the pressure in the fuel rail is low, there will still not be enough fuel.
The reason for jerking while driving may also be in the electromechanical part of the throttle valve or. The reason for such contamination can also often be caused by a lack of pressure in the fuel rail. When you sharply press the gas pedal, in order to instantly accelerate, it opens very wide, while the ECU, having received a signal from the TPS about the position of the damper, without having the necessary pressure, is simply not able to provide the engine with the required amount of fuel.
In cars with automatic transmission, the car jerks when accelerating due to a faulty gearbox or, for example, due to excessive low level oil in it. Sometimes "jokes" with the box can occur after disconnecting the battery immediately before the trip, this phenomenon is "not fatal" and as practice shows, it goes away by itself, after several accelerations.
Often the reasons are quite banal, for example: the mesh is clogged fuel pump and so on. But I think that you, like most of us, first checked it, if not, then by all means do it.
The car twitches on the go - reasons
As a rule, such jerks occur due to a malfunction of the ignition system. However, if the trouble happened on the road, you can try to fix the breakdown yourself. To do this, do the following:
- Switch off the ignition, raise the hood and make sure all high voltage wires are securely attached to the coil and spark plugs.
- Then start the engine and listen to the operation of the engine, listen for any extraneous crackles or clicks. The point is to check if there are any "breakdowns to ground", that is, if the spark leaves somewhere other than the candle. This is best checked in the dark, then you will not only hear a crack, but also see how it hits, for example, on the body or somewhere else.
Various malfunctions associated with the operation of the engine, transmission and attachments can manifest themselves both on Idling, and under load in motion, as well as in transient modes. Breakdowns can often be identified by the presence of obvious leaks of technical fluids, obvious knocking, precarious work, failures, etc. Next, we will consider the possible reasons why, while driving, a car with an injector begins to twitch, that is, noticeable jerks appear.
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Fuel system problems
If the car twitches while driving, then the diagnosis should start with. The main symptoms of engine power system malfunctions are jerks of the car in motion. These signs of breakage appear in several situations.
- There is a need to accelerate dramatically. At this moment, the driver presses the gas pedal hard, but the desired pickup does not occur. Instead, the vehicle jerks and then accelerates with or without further jerks. It is also possible that the jerks start after the throttle is released.
- The problem is reported when the car suddenly jerks while driving at cruising speed. In other words, dips and jerks in ICE operation can be noticeable both at the moment of speed change (during acceleration and gas release), and at constant engine speed (the gas pedal is in one position).
The first step is to eliminate the likelihood of refueling with low-quality fuel, airing the fuel supply system and leaks fuel lines... The next item to be monitored is the fuel filter.
In the event of a decrease in its throughput, the engine will not have enough fuel, especially with a sharp increase in speed and an increase in the load on the power unit. You also need to make sure that air filter does not have significant pollution.
After eliminating the above reasons, you must proceed to check the injector. To obtain accurate results, the fuel pressure in the fuel rail (rail) is measured, and the performance of the injectors is checked.
Low pressure in the fuel rail leads to the fact that at the moment of a sharp pressing on the gas, the throttle valve opens wide, the throttle position sensor sends a signal to. At a reduced pressure, the electronic control unit is not able to quickly provide a supply in the proper volume, as a result of which the machine begins to jerk on the go.
The engine can also run erratically and jerk on the move if there is a problem with. In addition to jerking, there is a loss of power, increased consumption etc.
Self-check involves diagnostics of power wires, spark plugs, ignition coils, DPRV. To find a possible cause, it is necessary to turn off the ignition, after which the reliability of the fastening of high-voltage wires on the coil and candles is checked. Then the motor is started and its work is assessed by ear. Special attention should be paid to the kind of "crackles" that can occur as a result of the fact that a spark breaks through in some area.
Then the spark plugs are unscrewed to inspect their condition. The destruction of the insulator and other defects on the candle body, as well as the erosion of the electrodes, are not allowed. You should also pay attention to carbon deposits that may be present on candles.
Such carbon deposits are removed mechanically with a stiff brush. If the car does not stop twitching after cleaning or replacing the spark plugs, then it will not be superfluous to check the camshaft position sensor with a multimeter.
Other reasons
Among the others possible reasons that can cause the car to jerk when driving, it is necessary to highlight possible problems with clutch on "mechanics" and malfunctions automatic boxes gear.
Concerning mechanical transmissions, jerking may occur after shifting to a certain gear at the moment when the driver starts to release the clutch pedal. In this case, you should start by checking the condition of the basket, clutch disc, release bearing etc.
If the car with the "automatic" moves in jerks or jerks during acceleration, then it is necessary to diagnose the gearbox, check the level transmission oil and the operability of the control electronics.
Finally, we add that noticeable jerks during braking by some drivers are mistaken for malfunctions of the internal combustion engine. In fact, worn brake discs can be a common cause of this behavior.
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When the gas pedal is pressed sharply, the engine jerks, jerks and dips appear, the car does not pick up speed: the main causes of the malfunction and diagnostics.
Almost every driver was faced with such an unpleasant situation when the car began to twitch during acceleration, at low speed, or even at the very beginning of the movement. Experienced car enthusiasts say with confidence that such a nuisance can happen to any car, regardless of age and brand. Jerks in motion can be traced both in the Chevrolet Niva and in any other car. If your car starts to show jerks on the move, it is recommended to find the cause as soon as possible and eliminate it in time.
Often, every driver can eliminate such an ailment without the help of specialists in the service station. Ignoring the problem can not only aggravate the situation, which in the future will require expensive repairs, but also jerking the vehicle often leads to an accident. Faulty car unable to start a smooth ride followed by acceleration. Twitching transport brings not only fear and horror to other road users, but also confuses them. Next, let's try to figure out what can cause the uneven course of the car.
At the first stage, the machine is diagnosed. Let's say that you have a Niva in your garage with carburetor engine... Your car already at the first stage of movement from a standstill shows signs of "illness". Or the car started moving without hassle, and when a certain number of revolutions were reached, the engine malfunctioned. All this will not give answers, but only create questions, because anything can break. Anyway, if seen unstable work power unit car while pressing the accelerator pedal, first of all, you should:
- Check air and fuel filters. The supply of air and fuel for the formation of a combustible mixture will be difficult if these elements are heavily contaminated.
- Check the fuel pump. Its incorrect operation leads to an unstable fuel supply.
- Check fuel pressure. The flow of the fuel-air mixture under insufficient pressure often leads to jerks of the car. The pressure when the engine is running should not exceed 3 kgf / cm2.
Most of the reasons lie precisely in the fuel system of the car.
do not write off the ignition system, and sometimes even the transmission can cause discomfort while driving. There can be many reasons. To narrow the circle of suspicion, measure the conditions during which the car begins to "be capricious." To do this, while driving, watch the dashboard and remember at what moment the uniform motion stopped. Repeat this several times to confirm that the observation is correct.
Eliminate jerks when the car starts moving
According to the number of reviews from the owners of the Chevrolet Niva with a carburetor engine, it is the motor power system that most often conceals a problem. Due to the breakdown of absolutely any element of the system, the stable process of fuel combustion in the cylinders can be disrupted. If an insufficient amount of mixture enters the cylinders, then the car in such conditions will not be able to deliver the required power. Against the background of this problem, twitching will begin to appear.
Check the pipes, determine if there is a depressurization in the system. Measure the fuel pressure. If the indicator does not correspond to the norm, then further search for the cause should be sought in the pressure regulator, fuel pump. These actions must be done not only with the carburetor system, but also with the injection system. If an injector is installed on the Niva 21214, then in this version the ignition system is also connected. Any sensor that is out of order can cause the car to jerk. Perhaps, in this case, you will need the help of specialists, because all the work is complicated by the presence of an electronic unit.
Eliminate jerks when accelerating a car
If the Niva 21214 begins to show jerking when picking up speed, then in this case it is necessary to carefully check the engine power system. The driver presses the speed pedal while driving, but the vehicle does not accelerate. By pressing the accelerator pedal, the driver provokes an increase in the amount of fuel mixture supplied to the cylinders. If this does not happen, breakdowns occur in a uniform course.
We check all filters: fuel, air. The carburetor motor has 2-3 filters. We will not take into account the mesh in the throat, since it is capable of preventing the penetration of only large particles. Carefully check the filter that goes to the fuel pump. It is often clogged with impurities, which ultimately impedes the free flow of fuel, because of this, the engine begins to "starve".
Eliminate jerks with stable car movement
If a Chevrolet Niva or Niva 21214 shows twitching during stable movement, then this most often happens due to problems with the ignition system. You can often hear complaints from car owners that, they say, they just put new candles on, and the engine has already malfunctioned. Detonation can occur even with new spark plugs due to incompatibility with the engine. If the candle is out of order, then the fuel will not burn completely, and breakdowns will begin in the operation of the power unit.
Checking the candles is easy enough. The first step is to:
- Check the level of the gaps on the unscrewed spark plugs. Check if there are any irregularities in the process sparking.
- A working candle gives off a spark of dark blue color.
- If the spark plug has black carbon deposits, then the problem may lie in a downed ignition or faulty mixture formation.
If checking the spark plugs does not bring any results, you should check all the wiring for oxidation and breakdowns. Do not forget about the coil, the toggle switch. All elements of the ignition system, as in the case of a problem in the power supply system, are thoroughly examined and checked for correct operation.
Conclusion
It is in the interests of every car owner to keep his car running like clockwork. But sometimes problems arise. If your car starts to twitch, then start diagnostics from simple to complex... Sometimes the problem can be on the surface. But it is not uncommon and difficult cases when serious car repairs are required. Transmission problems are the least common. In cars with manual transmission the clutch can be the cause of the twitching, namely the driven disc wears out.
Lack of oil in an automatic transmission also often brings such troubles. These are the main reasons that most often bring headaches to the owners of the Chevrolet Niva, Niva 21214. If, after doing all the above operations, it was not possible to find and eliminate the cause, then it is best to contact a specialist for a deeper diagnosis of the car.
The jerking of the car during acceleration can be caused by various reasons. In most cases, to detect 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 eliminate the malfunction as quickly as possible, otherwise there is a possibility of getting more serious problems.
Dips and jerking on a carburetor engine
If the car jerks during acceleration and further acceleration, and there are also dips when pressing the gas pedal, first of all, it is recommended:
- Check or replace air and fuel filters. When they are heavily contaminated, the supply of air and fuel becomes difficult, 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. Replacing it allows you to solve the problem with jerks of the car.
- Insufficient fuel pressure. The fuel pressure is checked by connecting the pressure gauge to the fitting on the fuel line (for this, a piece of hose is used). 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 looked for in the following vehicle components: fuel pressure regulator, fuel filter or a fuel pump.
The reasons for "failures" (when you press the gas pedal, the car refuses to accelerate) and the accompanying jerks are often:
- Ignition coil together with high-voltage wires, which, due to long-term operation and wear, begin to "punch", 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 in the car as a result of heavy carbon deposits 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 tightly as possible to the so-called. a metal penny placed in the tip of the wire.
This penny is designed to transmit current to the spark plug, and if there is no contact between the wire and the penny, then the current may not flow, resulting in triplet. 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 jerking on injection engines
Compared to carburetor versions, injection engines have better technical and performance characteristics... However, they also have a more complex design, therefore, the reasons that cause the car to jerk during acceleration can be much more 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. The jerking of the car mainly causes 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 termination of the injector, respectively, the possibility of starting the car is completely excluded.
DPKV is checked by connecting a car oscilloscope to it. If the sensor is in good working order, clear pulses of the injector operation will be displayed on the device screen. In the absence of impulses or their blurring, it is necessary to promptly replace / repair the sensor. It is also advisable to carry out an additional check of the operation of other controllers, which can make it possible to determine malfunctions of the oxygen sensor or, for example, the electric valve of the injector, which can also lead to jerking of the car.
The reasons for jerking injection machines, as well as for carburetor Vehicle, there may be problems in the ignition system (plugs, ignition coil, high-voltage wires), as well as malfunctions fuel system(clogged fuel injectors and filter).
Another common reason for the appearance of machine jerks is the use of low-quality fuel. Such fuel leads to the formation of a lean mixture, the characteristics of which are not sufficient for stable and high-quality engine operation.
In most cases, it is possible to eliminate the problem of jerking the car during acceleration quickly enough, the main thing is to start producing renovation work and prevent the occurrence of more serious malfunctions.
