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Floating idle speed. Why do turns fall? Why the revs are reduced when moving

Need all systems power aggregate worked regularly. In this case, the engine must work normally both under load and in idle mode.

In practice, often the drivers face a problem when the engine turnover is not falling or falling with a large delay after discharge gas. It is obvious that overestimated idling Indicate problems and are the cause of increased fuel consumption.

In this article we will talk about why motor turns do not fall, as well as consider the main reasons why arise similar problems on and auto.

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When resetting the gas, turns are increased or "hang": common malfunctions

Let's start with the fact that on many cars with an injector during heating the turns raises. This is necessary in order for the power unit to work steadily after a cold start.

However, after increasing the temperature, the control unit lowers the turnover of XX, bringing them to normal. On many cars with a carburetor, the driver independently increases the revolutions during heating, using the so-called "SUPPLC".

At the same time, after the engine is heated, the idle speed is normal, on average, 650-950 rpm. If you click on the gas and release the accelerator, the turns should be increased, after which it is again dropped to the specified values.

It also often occurs when the momentum is slowly reset or constantly held at a mark of 1.5 thousand rpm, 2 thousand revolutions, etc. Expensely, in such cases, the flow rate is increasing and is stronger than the DVS, which indicates the need for diagnostics.

So, let's start with frequent problems Carburetor. Often the engine speed is not discharged due to the problem with the throttle. For example, when the driver presses the gas, the damper must be opened wider so that more air to burn the fuel in the cylinders. After the gas pedal is released, the damper is closed, revolutions are reduced.

If the damper does not close to the end, the re-entered mixture is incorporated into the cylinders, revolutions are increased. The reason may be strong pollution of the throttle node or damage to the damper itself (deformation). To begin with, clean the flap, the liquid for cleaning the carburetor is suitable as a cleaner.

We also note that the damper is closed and in the case when the drive cable is worn. In this case, the cable is subject to replacement. On carburetor machines do not fall engine speeds often and in the event that the gasket between the carburetor and failed. Also, the culprit may be an intake manifold, which has damage.

The main task becomes the right ratio of the amount of fuel and air. Often the high level of fuel in the carburetor float chamber also leads to increased revs. Check should be started with a needle valve.

We now turn to the injector. Pay attention to many injection cars. As for malfunctions, the injection system itself is more difficult, that is, the causes of high revolutions are more compared to the carburetor.

As a rule, circulation problems can be caused by malfunctions of both mechanical elements and electronic components. In the list of major malfunctions, experts identify disorders of the temperature sensor, which is installed in.

Similar words, if the specified sensor supplies an incorrect signal, the ECU believes that the engine is cold and uses the warm-up mode. In this case, the control unit raises the momentum so that the power unit worked stably and faster to operate.

Also, revolutions problems may begin due to problems and failures in the work (idle regulator). It also happens that the throttle cable is hired and twisted. Still spring that closes throttle valvemay stretch or turn out to be damaged.

Separate attention should be paid to the gaskets, since the air drums can lead to the fact that the mixing formation is disturbed. This means that you need to separately inspect the laying of collectors, nozzles seals, etc.

Floating turnover: Causes

Note that in some cases, the turnover is not just slowly falling or kept at one level, but "float". In this case, the engine can work unstable. First fall, then grow sharply and everything is repeated. Frequent cause of such a phenomenon is the supply of excess air, which leads to the "jumps" of turns on the XX.

Such problems arise in case of failure of the air supply sensor (), which allows the ECU to calculate how much air has been received and how much fuel is applied to prepare the necessary mixture.

If the failures arise, the control unit cannot prepare the "correct" mixture for the XX mode, which causes speed jumps after the release of the gas pedal or during the operation of the motor at idle.

Let's summarize

As you can see, to accurately determine why the engine turns are not reset, in many cases there may be in-depth diagnosis. For carburetor engines, cleaning and adjustment of the carburetor itself is often needed, while for the injector it will be necessary.

If the problem does not lie on the surface (zakis the valve cable, after washing or dry cleaning, the mat is incorrectly laid in the cabin, which presses the gas pedal, etc.), then it is better to deliver the car to the service.

The most difficult situation is such when it assumes the presence of a large number of sensors and actuators. In this case, even use diagnostic equipment It does not always allow you to quickly and accurately determine the problem.

If the diagnosis is difficult to optimally deliver the car to such a service that specializes in repair concrete brand cars. As a rule, these are official dealerships, less often you can meet third-party organizations.

Finally, we note that the timely detection of the problem allows you to save other nodes and aggregates. In other words, high curvatures of XX, speeding turns and jumps indicate that there are problems with air / fuel supply or with mixing formation. Ignoring such problems negatively affects the engine and the service life.

Perhaps the case is not in the technique, but in refueling?

As mentioned above, the carburetor is very sensitive to the quality of gasoline, which you pour into the tank of the car. If sacrifice or impurities come out, the technique will not work normally. Dirty gasoline to a certain pore is cleaned with a filter, but over time, such a cleaning ceases to help. Fuel with impurities and inclusions may be a big problem that affects not only the revolutions. Here are several important indicators Such a problem:

already a few kilometers after refueling by poor-quality gasoline, you will feel changes in the dynamics of the car, the fuel consumption will increase and stability will deteriorate;
engine turnover at idle can swim, and it will talk about the unstable fuel mixes, at speeds are also small jerks and failures in the aggregate traction;
after cooling the engine at the next start, the warming can start unexpectedly with low revolutions, you will have to play a suction in unusual ranges to warm up;
it is also possible that after warming up to 30-40 degrees, a failure will arise, which will need to be compensated for by pulling out the supply until it stops or podging the foot;
when warming up operating temperature The motor will work relatively stable, but the speed of revolutions will remain, it is these indicators of poor-quality fuel in a car tank.

These criteria suggest that it is better not to go to the usual refueling for you. Of course, the same problems are possible if the carburetor fails and needs maintenance. But often these problems arise precisely with poor-quality fuel with a low octane number or with impurities. Therefore, the first thing is to roll out the gasoline on a heated motor and add good tested fuel to it.

It is time to serve the carburetor - small defects

The reason for the fall of revolutions during warming can also be a small breakdown in the carburetor system. These are broken membranes, mixed fastening of cables or the showering of the damper. Such troubles can be cured during revision this device. In the old days, every second driver of the car could independently sort out the carburetor, install Remkomplekt and go further, listening to the satisfied rumbling of the aggregate. Today the principle of repair is as follows:

you should go to the automotive store or market to find a suitable repair kit for your type of carburetor, it is better to take original high-quality details;
it is further important to find a wizard who is well versed in carburetors and can help eliminate problems in your device, such masters in cities are less and less;
a specialist for several tens of minutes will move the equipment, will find a problem and establish new gaskets, membranes, seals and other products from the repair kit;
next, it is necessary to check the equipment to make sure that there is no unpleasant effects, it can often be done only the next day on the cooled car;
the last step is regular visits to the master 1 time in 2 years for maintenance and revision of the carburetor, this will allow you to save the car in a normal working condition.

There are advantages in the fuel injection carburetor injection. For maintenance and cleaning the injector will have to pay a whole condition. But the repair of the carburetor even with the replacement of certain parts will not cost too expensive. But to get these advantages, find a master who is well familiar with the features of your car model. Such a specialist will help to correct all problems and continue to exploit the car without problems.

Condensate or dew point - is it possible?

On VAZ 2107 cars, the engine revolutions is very often occurring while warming up until the aggregate stops. Such trouble is characteristic of all carburetors, except for Saleks. The problem is that at temperatures from 0 to +5 degrees in the chambers of the carburetor, condensate can be collected. This is a specific type of dew, which is formed during temperature drops. After starting the motor to the cold, the following process occurs:

first, the open sublicas launches the enriched mixture, which without problems burns and does not cause tangible changes in the operation of the power unit, which is very important for normal launch;
as the owner of the car lowers the sublicas, the mixture is approaching the characteristics to the worker, and the entire engine system is already a little fundamental, and the most interesting thing begins here;
condensate or dew start to enter this mixture and change its properties, in some models of devices it happens quite quickly and unpleasantly, causing a stop of the motor;
the driver again pulls out the seats or presses the gas pedal, the mixture is enriched, the motor is working normally, but up to 60-70 degrees this process may be repeated infinitely;
after warming up to about the operating temperature, everything is normalized, the revolutions come back to normal, the engine works well, so when a visit to the station, the wizard will not detect anything.

How to deal with such a situation, it is difficult to even imagine. The only one in an effective way There will be a replacement of the carburetor to the Solex, but also in these models there are often problems with the launch of the power unit in transition temperatures. So give any specific tips in this case not so easy. Best to maintain equipment in time and always support fuel equipment in good conditionThis will help to get due reliability of the machine.

Are there any other reasons for a sharp drop of revolutions?

The causes of such trouble can be a whole set. If you repair the car yourself, it is worth a slightly look at trouble and try to find reasons in other nodes. But it is worth moving onto other features of the car only if you were convinced of the high quality of the carburetor, normal fuel and other features mentioned above. Here are some more ideas for checking:

fuel filters - very often filter elements are clogged, and the owners forget them to change in time, and it leads to serious problems with vehicle;
the thermostat is possible after a minor habit of a small circle, your thermostat opens and keeps sharply ice fluid into the engine, which leads to a drop of revolutions;
electronics - It is worth checking the ignition, a normal timing belt setting, no problems with sensors and various electronic equipment on board your car;
the inclusion of electricity consumers - perhaps, in your car automatically turns onto a powerful device, which gives the load on the unit, the revolutions are inevitably falling;
the valve system - sharp drops and drops in this case will not be, but floating and unstable turnover are quite possible, and with the load they will turn into a fall.

The reasons for the instability of the engine operation can be a lot. Sometimes the problem is that the generator at a certain point ceases to give normal voltage, which affects work electrical systems Engine. Motor load can also be due to bad oil or interior breakdowns In the cylinder block or in the valve system. So you can dig in this case for quite a long time, and it is better to visit a hundred and find the cause of the problem.

We offer to watch a video with a solution to one of possible causes This problem:

Let's sum up

There are dozens of breakdowns that lead to a sharp or smooth drop of revolutions on carburetor cars. But the question is that the equipment turns out to be quite demanding for service, therefore, it is necessary to eliminate all the reasons to be taken together. If you always encounter such a problem, it means that this is the specifics of the carburetor, installed in your car. Most likely, only replacing the device will help get rid of trouble. If the trouble arose only a few times, it is worth trying to serve the fuel system, replace the filter and install a new carburetor repair kit.

Auto with such a type of injection is gradually inferior to injection systems. They are more reliable, more economical, serve longer and do not bring such trouble as carburetors. Of course, B. direct injection Also many subtleties and features that should be remembered. But changing the carburetor on the injector is too labor-intensive and expensive. It is better to maintain your technique and achieve its normal work. Even with very good services, after 1-2 years, you will have to go to the service again. Have you ever encountered a sharp drop of engine speed when warming up?

Many motorists are wondering why idle turns fall. The drop of engine revolutions may happen different reasons. Surely every motorist noticed such a behavior of the engine, for example, when it is on the traffic light.

This article will be considered frequent reasons Motor turns.

Why the engine turns fall

Embossed fuel

Very often, the reason for the fall or swimming engine turns lies in poor fuel. If you refuel at different gas stations, you noticed the difference as fuel. Everyone knows that in the countries of the former USSR, the owners of petrol stations love to chealing on gasoline. Because of this, the engine of your car suffers. And if gasoline is poor quality, then problems with the fuel system may appear. Try to fill the car to another petrol station And compare: if the difference is absent, then continue to read the article on.

Fault in the fuel supply system

Due to poor quality fuel some elements fuel system Can stop functioning normally. Try changing fuel filters, it can help. If this does not help, then you will have to do the revision of the fuel system.

The problem may still be in the uneven supply of fuel in the cylinders. In this case, you should go to the station maintenancewhere the specialist will eliminate the problem. Do not try to do it yourself: you can deal with your actions injector.

It is worth checking the pressure in the fuel ramp: Connect the pressure gauge, write down the results and compare them with the valid results that should be in the instruction manual for your car.

The problem may also be in fuel pump. It can swing fuel unevenly, and due to this can fall engine speed.

Malfunction in the gas distribution mechanism

Over time, the operation of the gas distribution mechanism can break. You will have to re-exhibit the gas distribution mechanism by tags. The case can reach the cleaning of the valves and the intake manifold from Nagara. If the engine has not been repaired for a long time, there can be quite a lot in the collector in the collector.

Fault in the air supply system

The problem with the air flow sensor may also cause the incidence of revolutions. In order to check it, to the yellow wire that goes to the sensor, connect the plus contact of the tester, the minus - to the battery. The voltage must be from 0.98 to 1.02 volts.

The malfunction can also be wounded in the oxygen sensor or in the engine temperature sensor, which calculate the number of revolutions when driving the engine. Also, the problem may be different compression in the engine cylinders. Due to uneven compression, the engine begins to work unevenly.

During the operation of the car, drivers have to deal with various problems. One of the faults that is quite widespread is the constant maintenance of high revolutions. That is, even at idle the engine turnover does not fall. Such a problem may be observed both in injection and in carburetor engines, but the reasons will be different. As part of this article, we consider the symptom of which malfunction is this problem, and how can you get rid of it.

Table of contents:

How to diagnose that do not fall at idle speed

Related that even an inexperienced driver does not fall at idle the drive of the car. It is easy to determine the rumor, because, as you know, the lower turnover, the quieter works the engine. In addition, if the car is equipped with a tachometer, it is possible to determine the number of revolutions per minute at a specific point in time.

Depending on which engine is installed in the car, the revolutions rate per minute at idle can vary. On average, it is believed that the engine is working normally when the turnover is at idle from 650 to 950 per minute. If the turnover is higher (unless otherwise noted in technical passport To the car), then this can be called a deviation.

Please note: on most cars with injection engines at high idle speed lights the "Check engine" on the dashboard lights up.

What are fraught with high idle speed

The first one worth remembering the driver is about high consumption Fuel at elevated revs. Accordingly, if high speed is kept at idle, it means that partially fuel "flies into the pipe". In this case, this problem directly affects the resource of the engine, which suffers from such a malfunction. Also, the node itself may also suffer, which led to the emergence of the fault. That is why, in case of identifying this problem, it should be fixed as soon as possible.

Why do not fall at idle driving engine

Currently carburetor engines are practically not used in modern cars. Nevertheless, it is necessary to consider why there may be a problem with high speed at idle in such engines, since most of the problems echoes injection engines. If such a malfunction occurs, attention should be paid to the following elements:

The above is considered most of the problems that lead to high revolutions At idle in the carburetor engine. Also impossible to exclude total problem For carburetors and injectors - gas pedal jamming.

Why do not fall the speed at idle the injection engine

Now consider the faults that lead to high speed turns in injector Engine. Unlike carburetor motors, where all mechanical problems, in the injector, the malfunction may be associated, including with incorrect operation of electronics. The main reasons are as follows:

As you can see, problems, because of which the speed is not reduced at idle, quite a lot. If such a malfunction arose, it should be proceeding as quickly as possible to search for its reason to prevent even more serious problems.

Very many owners of used cars are familiar with such a problem as "floating" idle speed. Such a trouble may occur both on completely old cars that are equipped with a carburetor and more modern, which are already working on the injector. Immediately make a reservation that it is much cheaper to solve the problem on the carburetor engine much cheaper and easier, but what are things with injection motors, we will try to figure out.

First you need to pay a little attention to the injector device. If you pose an analogy with a carburetor, then, speaking in a simple language, it can be said that the carburetor has a fully mechanical control, i.e., the driver himself controls the subference, adjusting the power supply to the engine cylinders. In the injector, all "mechanical" commitments take electronics. Of course, the electronics, or the microcomputer, controls the control using several installed sensors, and so if the latter begin to work incorrectly, or they stop working at all, problems with revolutions begin, since the control computer simply cannot determine what to do.

Possible causes of "floating" idling

As already mentioned, the most vulnerable link system electronic control are. One of the main is the idling sensor. As a rule, this sensor is attached in the area of \u200b\u200bthe control sensor. Checking the sensor is carried out using a multimeter. The procedure for checking the sensor is quite simple. It is necessary to measure the resistance between the contacts, which are included in the sensor block. At the same time, the ignition of the car must be turned off. Conditionally contacts have the designations of A, B, C, D. Resistance between contacts must be in the limit of 40 to 80 ohms. If during the measurement you received other readings, it means that the idling sensor needs to be replaced.

Another sensor, which is quite often "Handyr" is a sensor mass flow air, or DMRV. To test the operation of the sensor, you need to turn on the ignition, but do not start the engine. Voltage is checked by a multimeter known to us. It is necessary to measure the tension of the contacts to which the green and yellow wire are connected. The permissible value of the DMRV sensor is from 0.9 to 1.2. In addition, the sensor malfunction can also be determined along the ignition candles. If there is a black coal carbon black on them, it can also be a signal that it is necessary to replace the faulty sensor.

The less common cause of uneven idolotes of the engine may be a violation of work in eGR system. This sensor is located in the inlet and is responsible for the output. More precisely, the sensor is responsible for the withdrawal of most of the exhaust gases, and a slight number again pours into the engine cylinders to reduce the amount harmful emissions In the atmosphere, as well as achieve complete combustion and energy estimation of fuel. It is recommended to periodically clean the sensor to maintain its normal operation.

Why are the sensors fail?

There are 2 main reasons for the output of the sensor. First, it is a low fuel quality: all sorts of additives that contain domestic gasoline, its low octane number Not only clog the sensors, but also the cause of disruption of the operation of electronics. Secondly, the sensor may fail due to the exceeding its resource of the work, which is a completely natural reason. Installation of a low-quality, or defective sensor is granted.

A little about replacing the sensor

If, in the case of the carburetor engine, everything is simple, you can do without stands and make all the repair at home, then with the injectors the situation is much more complicated. First, the sensors themselves, which are only a small link in the chain of the DVS, are a solid money for which, for example, you can spend overhaul Carburetor. Secondly, replace the sensor in garage conditions It is impossible, since after the corruptible work of its replacements and connectivity, it is likely that the injector will need to be re-entered in order to achieve a complete "recovery" of the car. Of course, such work is carried out using computer-diagnostic programs.

Fortunately, the sensors have a fairly solid service life and are able to not deliver problems to the owner of the car of about 150-200 thousand km. However, if you are the owner of a far from a new car, with a rather impressive digit on the odometer, be prepared for the fact that there may be malfunctions very soon.