Often, car owners are faced with such a malfunction when, when the gas is released, the engine speed does not drop, more precisely, it does not drop to the normal idle level (XX). This applies to both the fuel injection system and the carburetor.
Usually idling gasoline cars, depending on the motor model, are in the range of 650-1000 rpm. Any deviations from these indicators indicate incorrect operation of the vehicle's power system. It is not worth delaying the elimination of this malfunction, since increased engine speeds lead to an increase in fuel consumption in the car and accelerated engine wear, which negatively affects the financial condition of the driver.
Sometimes the reason may lie in excessive enrichment. fuel-air mixture supplied to the cylinders. This provokes an increase in speed to a certain level, after which the engine begins to "choke", thereby reducing the speed to a normal value, after which they rise again. This malfunction causes the effect of "floating revolutions", but the problem may lie in other violations of the power system. In addition, do not forget that malfunctions in cases with injection and carburetor engines will be different.
The main engine problems with a carburetor power system
- The location of the needle valve responsible for adjusting the level of gasoline in the float chamber.
- Leaky closure throttle valve, which often happens when it is clogged or mechanically damaged. A dirty throttle should be cleaned with a special tool that can be purchased at an auto parts store. And in case of mechanical damage to this node, most often, it is required complete replacement carburetor.
- Incorrect adjustment of the XX system. This problem often appears after cleaning or replacing the carburetor. To eliminate it, you just need to adjust it, providing the optimal ratio of gasoline and air in the fuel-air mixture.
- Consistently high idle may indicate a loose throttle valve located in the primary chamber. This problem appears due to wear of the throttle cable or deformation of the damper itself.
- Damage to the intake manifold or worn gasket between the cylinder head or carburetor.
In the case of an injection power system, there are much more possible reasons for an increase in idle speed. This is due to the fact that they can be associated with both the failure of mechanical components and the malfunction of electronic sensors.
The main malfunctions of the injector
- Faulty coolant temperature sensor. Interruptions in the operation of this sensor lead to the fact that the motor constantly operates at high speeds, in warm-up mode. However, after warming up power unit up to operating temperature the electronic unit control does not reset the speed to normal values, since the sensor signals that the engine has not yet warmed up. The same thing happens when the idle speed controller does not work properly.
- Stuck throttle cable. This happens especially often on cars with high mileage.
- Violation of the operability of the XX regulator or its electronic sensor, while the turnover on Idling may increase or disappear altogether.
- Throttle position sensor malfunction.
- Jumping or excessive stretching of the return spring, which should return the damper to its original position.
- Violation of the integrity of the gaskets, rubber seals of the nozzles or the manifold itself. With these malfunctions, excess air from the environment enters the combustion chamber.
The most common reason that the engine speed does not drop to idle when you release the gas may be inaccurate placement of the mat under the accelerator pedal after visiting the car wash.
Summing up
First of all, a malfunction of the injection and carburetor power systems should be diagnosed by inspecting the throttle.
In the case of an injection engine, it will help to accurately determine the malfunction of a particular sensor. computer diagnostics. To do this, it is best to use the services of a service that specializes in servicing cars of a particular brand.
During the operation of the car, drivers have to deal with various problems. One of the faults, which is quite widespread, is the constant maintenance of the engine high speed. That is, even at idle, the engine speed does not fall. Such a problem can be observed both in injection and carburetor engines, but the reasons for this will be different. In this article, we will consider what kind of malfunction this problem is, and how you can get rid of it.
Table of contents:How to diagnose that idle speed is not falling
Even an inexperienced driver can easily notice that at idle speed of the car, the speed does not drop easily. This is easy to determine by ear, because, as you know, the lower the speed, the quieter the engine runs. In addition, if the car is equipped with a tachometer, it can be used to determine the number of revolutions per minute at a particular point in time.
Depending on which engine is installed in the car, the rate of revolutions per minute at idle may vary. On average, it is generally accepted that the engine is running normally when the idle speed is between 650 and 950 per minute. If RPM is higher (unless otherwise stated in technical passport to the car), then this can be called a deviation.
Please note: On most fuel injected vehicles, the "Check Engine" light on the instrument panel will come on at high idle.
What causes high idle speeds
The first thing the driver should remember is the high fuel consumption at high speeds. Accordingly, if high speeds are maintained at idle, this means that part of the fuel "flies into the pipe." Moreover, this problem directly affects the resource of the engine, which suffers as a result of such a malfunction. The node itself, which led to the occurrence of the malfunction in question, may also suffer. That is why, if this problem is identified, it should be fixed as soon as possible.
Why the idling speed of the carburetor engine does not fall
At the moment, carburetor engines are practically not used in modern cars. However, you need to consider why a high idle problem can occur in such engines, since most of the problems overlap with injection engines. When such a malfunction occurs, pay attention to the following items:
Above are most of the problems that lead to high idle speeds in carbureted engine. Also, a common problem for carburetors and injectors cannot be ruled out - jamming the gas pedal.
Why the idle speed of the injection engine does not fall
Now consider the malfunctions that lead to increased idle speed in injection engine. Unlike carburetor engines, where all the problems are mechanical in nature, a malfunction in the injector can be associated, among other things, with incorrect operation of the electronics. The main reasons are as follows:
As you can see, there are a lot of problems due to which idle speed does not decrease. If such a malfunction occurs, you should start looking for its cause as soon as possible in order to prevent even more serious problems.
Almost every owner of domestic vases faced the problem of high idle speeds. That is, when the engine is started, the revolutions are as high as they should be, however, when the engine warms up, they do not fall below 1500 or 1000 revolutions, which is not normal. There may be several reasons for this - and a malfunctioning TPS and idle speed controller.
To fix the problem, you should diagnose the main components and components that affect the increase in speed.
Why can there be high idle
One of the main reasons may be the failure of the IAC - the idle speed controller, it is he who is responsible for adjusting the engine speed at idle. At , the revolutions can “float”, increase and decrease spontaneously. With a complete failure of the sensor, at idle, the car may simply stall.
Also, increased speeds can be caused by a malfunction of the throttle position sensor (TPPS). Over time, moisture gets under the sensor, which leads to the formation of oxide and rust on the regulator stem. To check this, you need to unscrew the sensor and carefully inspect it and the stem. If rust is found on them, they should be treated with a penetrating lubricant or WD 40.
As a rule, the problem of increased speed on the VAZ 2110-12 lies precisely in these two sensors. Therefore, first of all, you need to pay attention to them.
Where are the IAC and TPS sensors located
So, for starters, let's check the IAC sensor. It is located on the throttle assembly below the TPS sensor. Dismantling it is very simple - remove the block from the sensor and use a Phillips screwdriver to unscrew the two bolts of its fastening. Then we pull out the sensor or make its diagnostics, read about it below.
The throttle position sensor is located above the IAC and is also fixed with two bolts. It unscrews quite easily, there is no need to remove either the nozzle on the throttle or the throttle itself. Disconnect the block, unscrew the two bolts and pull out the sensor.
To make sure that the problem of high turnover is really in one of these sensors, and maybe in another right away, they should be diagnosed.
Diagnostics of the IAC 2110 sensor
It is possible in several ways. To check we need a multimeter. First, let's describe the simplest way:
IAC test method 1
- Disconnect the block from the sensor and unscrew the sensor
- Turn on the ignition
- We connect the block to the removed sensor, the needle in the sensor should extend, if not, then the sensor is faulty
IAC test method 2
- Disconnect the negative battery terminal
- Using a multimeter, we measure the resistance of the external and internal windings of the IAC, while the resistance parameters of contacts A and B, and C and D should have indicators of 40-80 Ohms.
- At zero values of the scale of the device, it is necessary to replace the IAC with a serviceable one, and if the required parameters are obtained, we check the resistance values in pairs B and C, A and D.
- The multimeter should detect an open circuit
- With such indicators, the IAC is serviceable, and in their absence, the regulator must be replaced.
IAC test method 3
- Disconnect the block from the sensor
- Using a voltmeter, we check the voltage - “minus” goes to the engine, and “plus” goes to the terminals of the same block of wires A and D.
- The ignition is turned on, and the data obtained is analyzed - the voltage should be within twelve volts, if less, then most likely there are problems with the battery charge, if there is no voltage, then you will have to check both the electronic control unit and the entire circuit completely.
- Then we continue the inspection with the ignition on, and alternately analyze the conclusions A: B, C: D - the optimal resistance will be about fifty-three ohms; at normal operation IAC resistance will be infinitely great.
Diagnostics TPS VAZ 2110
To diagnose the sensor, we need a voltmeter.
- It is necessary to turn on the ignition and check the voltage between the slider contact and the minus with a voltmeter. The voltmeter should show no more than 0.7 V.
- Now you need to turn the plastic sector, thereby completely opening the damper, then measure the voltage again. The device must show at least 4 V.
- Turn off the ignition and disconnect the connector from the sensor. We check the resistance between the contact of the slider and some output.
- Slowly, turning the sector, follow the readings of the voltmeter. Make sure that the arrow moves smoothly and slowly, if you notice jumps - the throttle position sensor is faulty and must be replaced.
Symptoms of malfunctioning DPS
- Deterioration of vehicle dynamics
- floating idle
- Jerks during acceleration
- Increased idle
- Engine may stall at idle
If one or more of the above symptoms are detected, the sensor should be checked and diagnosed in the manner described above.
Which TPS sensor to choose for replacement
- DPDZ / 2110 / GM 2112-1148200 price from 300 rubles
- DPDZ / 2110 / PECAR 2112-1148200 price from 200 rubles
- DPDZ / 2110 / StartVOLT VS-TP 0110 price from 200 rubles
- DPDZ / 2110 / HOFER HF 750260 price from 150 rubles
- DPDZ /2110/ CJSC Account Mash 2112-1148200-05 price from 400 rubles
- DPDZ /2110/ OJSC RIKOR ELECTRONICS 2112-1148200 price from 300 rubles
Replacing the Throttle Position Sensor VAZ 2110
Using a Phillips screwdriver, unscrew the two sensor mounting bolts, disconnect the block and remove the sensor.
If traces of rust or oxidation are found on the rod, which regulates the speed, it is necessary to clean it with a penetrating lubricant.
It is very important that the engine runs correctly in any mode, including idling. However, many car owners are faced with a problem: when the gas is released, the engine speed is not reset. As soon as such a defect is discovered, it is necessary to immediately find out the cause and eliminate the malfunction for the smooth operation of the car. Also, the engine can slow down for a long time, which also does not contribute to proper operation.
Usually, upon reaching operating temperature, the speed should drop to its norm. Indicators for each specific model vehicle the manufacturer specifies in the instruction manual. They may vary slightly depending on the mileage and the general condition of the car, but usually stay in the range of 650-1000 rpm.
In some cases, the speed drops very slowly or even stays at the same level of 1500-2000 rpm. In this mode, not only increases fuel consumption, which affects the finances of the driver, but also contributes to engine wear.
The reason for the failure in idle needs to be diagnosed with skilled craftsmen. However, to independently understand why the engine speed does not fall.
Malfunctions in the carburetor system
When releasing gas, the drop in speed can go badly on both injectors and carburetor systems.
If the car has a carburetor, then there may be several defects.
Most often, the speed is not reset due to a faulty throttle. When the engine warms up, it is in the open position to allow more air into the system. Then it closes and the speed should drop.
A throttle valve that is not completely closed leads to the fact that, upon reaching operating temperature, an over-rich mixture is still supplied, and the speed remains at the same level. If this part is heavily soiled or deformed, it cannot close completely.
You can clean the damper with special means, which can be purchased at an automotive supply store. Deformation may require replacement of the carburetor completely. The damper may not close tightly if the drive cable is worn out. Replacing it may improve the situation.
Another common reason why the engine speed does not drop at idle is a gasket between the carburetor and the cylinder head that has become unusable, or a damaged intake manifold.
After replacing the carburetor or cleaning the power system, you can often notice that the engine speed drops slowly. This is due to improper adjustment of the idle system, often a re-enriched air-fuel mixture is supplied. To fix the problem, it is necessary to adjust the ratio of the fuel and air supply to the system.
Also, a high level of fuel in the carburetor float chamber can provoke a defect in operation. The needle valve is responsible for it. Checking this detail may correct the situation.
Injector system
If the vehicle has injection system, then there can be much more reasons for high idle speeds. Here, both mechanical elements and electronic devices responsible for adjusting the twentieth can fail.
The main malfunctions of the injector include:
- Incorrect operation of the temperature sensor installed in the cooling system. Incorrectly received data from this device causes the electronics to recognize the engine as cold and work to warm up, thereby maintaining the high speed required to reach operating temperature. Overheating can often occur, which leads to more serious breakdowns, up to a major overhaul of the engine. The same effect is possible if the idle speed regulator does not work properly.
- The throttle control cable may be stuck. The higher the mileage of the car, the higher the risk of encountering a similar problem.
- The XX electronic work sensor often malfunctions, then the revolutions will either increase or disappear altogether.
- The spring that brings the throttle valve to its original closed position is not functioning properly, jumping off or stretching too much.
- Too much air enters the combustion chamber due to poor quality or leaky gaskets. It is necessary to carefully check the seals of the manifold and injectors.
- And the simplest reason is usually the wrong location of the mat after a visit to a car wash or dry cleaning of the interior. It is often inaccurately placed under the accelerator pedal, resulting in the appearance of improper engine operation.
If the car is oversaturated with a variety of electronics and all work is based on the correct functioning of the sensors, one of them may well become a problem. It will send incorrect data to the computer, as a result, the speed will not fall. Most likely, it will not be possible to detect the problem on your own.
It is necessary to contact a car service for computer diagnostics. Best of all, the task will be handled by specialists working at a service that specializes in repairing a particular brand of car. If the diagnosis is carried out on time, then it is quite possible to get off with a simple replacement of the sensor.
It is not worth delaying the repair, because a supersaturated mixture has a bad effect on the operation of the engine and significantly reduces its service life.
floating speed
In addition to slowly falling revs, motorists may encounter the phenomenon of floating revs when they fall and then rise sharply. The reason is the excessive air supply to the system, which causes the engine to spin up to 2 thousand revolutions at idle.
This often happens in vehicles that have a fuel injection sensor. It calculates how much air the mixture needs. When its work is disrupted, a different amount of oxygen is supplied at different times, as a result, speed jumps are observed approximately every 3 seconds.
Faced with a similar phenomenon, the same computer diagnostics will be a prerequisite. It is very important that it and all subsequent work is carried out by experienced, qualified specialists. By contacting a service that does not specialize in breakdowns of this kind, you may be faced with the need to carry out an expensive overhaul engine ahead of time.
The owners of front-wheel drive VAZs have enough troubles for the entire period of operation of the car. One of the most bothersome is high idle, moreover, on an already warm car. This problem usually causes annoyance, because the reasons for its occurrence are too many, and finding them is not easy.
Let's list them.
- The most basic is a malfunction or failure of the mass air flow sensor.
- It is not uncommon for the idle control valve to fail.
- The crankshaft position sensor, which gives incorrect information to the control unit, can also become the root of high or floating idle.
- The throttle position sensor could also be the culprit.
- It happens that for some reason the gas pedal does not return back to the end. Moreover, this happens both because of a banal malfunction of the cable, and because of a completely ridiculous one - for example, after washing the car, they laid the driver’s mat in such a way that the tip of the mat began to touch the pedal.
- Heavily clogged air filter. Because of this, the combustion mixture is too enriched with gasoline, again there are high revs during idling.
- Throttle cable came loose.
- Malfunction of the engine temperature sensor. It gives the "brains" of the car the wrong values, they increase the speed of the crankshaft, thinking that the engine is cold.
As you can see, we have a whole forest of various reasons why high speeds appear! Next, we will take a closer look at the most characteristic, plus the most common problems associated with the described problem. At the same time, we will figure out how to eliminate them with our own hands.
Ways to eliminate the "sore"
If such a nuisance happened, you need to analytically look for which node is to blame, checking all the indicated sensors.
To begin with, consider the following option to correct the problem situation. Suppose high speeds were found at the VAZ 2110. Inspection of the suspected components for malfunction showed that the throttle position sensor has traces of rust. It is located directly above the throttle valve. Measurements with a voltmeter showed that when the motor is idling, the voltage on it remains high - which means that it does not close the damper.
How to troubleshoot? To do this, we only need a screwdriver. Let's start the procedure.
- Having disconnected the terminal block, as well as unscrewing the two screws, we dismantle the assembly.
- We notice that traces of rust inside interfere with the wheel that regulates the position of the damper.
- We fill the insides of the defective device with a penetrating aerosol against rust.
- Scroll the wheel with a screwdriver for development.
- We assemble in the reverse order.
Check if the idle speed of the engine is now high. The problem should be fixed.
Now let's consider another case. Let's say we have high idle speeds in the VAZ 2114. Here's what we do when faced with this situation.
When clarifying the circumstances of the problem under study, we first always check the operation of the idle speed sensor. This device consists of a needle embedded inside an electromagnetic coil. The needle either moves inside the coil, moving away from the opening of the throttle pipe, or extends, closing this opening, thereby stopping the air supply for combustion of the mixture.
Also read about and.
This element is located at the throttle, opposite the gas pedal cable. To diagnose it, we pull out the terminal block from it, start the car, after which we see that we still have high engine speeds at idle. Then we remove this defective unit, then we clean it or replace it. For work we take:
- screwdriver
- toothbrush;
- petrol.
Getting started.
- Unscrew two screws. We get the broken knot.
- We connect the wiring to it. We turn on the ignition. If the needle of the device moves slightly inside the coil to the touch, then it is working.
- If the needle does not respond when an electric current is applied, wash the device with a toothbrush with gasoline.
- Assembly is done in reverse order.
When it is not possible to restore the performance of this node with your own hands, it is better to purchase a new one. Moreover, the cost of spare parts is low.
Other fixes
Of course, the options considered do not exhaust the possible ways to correct the shortcoming when high speeds are noticed precisely on a warm engine. To further study the most common situations, we will analyze the case of a malfunction of the mass air flow sensor. 
This device is responsible for supplying the correct portions of air for the combustion of the mixture, and also provides data to the electronic control unit about these portions so that the unit measures the supplied portions of gasoline.
This node can be diagnosed as follows. It is necessary to disconnect the terminal block from our mass flow controller, and then start the engine, after which it is necessary to drive at revs crankshaft above 2000 rpm.
This automatically starts emergency mode, portions of the mixture are now calculated only by the position of the damper. If the sensations showed that the car with the sensor turned off became more dynamic than with the one connected, then the malfunction of this unit is obvious. 
To replace it, we take the following tools:
- Phillips screwdriver;
- flat screwdriver.
We are starting repairs.
- After turning off the engine, disconnect the wires from the mass air flow sensor.
- After loosening the clamp, remove the hose on the intake pipe.
- We dismantle the defective device by unscrewing two bolts.
- We are replacing the device.
- We do the assembly, moving backwards point by point.
This is how this cause of high turnover is eliminated.
For some reason it didn't work
Now let's look at another situation. The car owner changed, for example, the idle speed sensor, while the crankshaft speed became high, or still remained elevated anyway.
The reasons for this unpleasant phenomenon may be as follows.
- Most likely, the motorist did the replacement just like that, at random, maybe it will stop turning too fast. The real state of affairs suggests that the malfunction must be sought elsewhere.
- If this sensor is not a completely new sample, it has an adjusting bolt, it may be necessary to tighten it in order to adjust the problem node. Modern idle valves do not require any additional adjustment when installed. However, for example, if Priora has high idle speeds, then this car you can look for the adjusting screw.
- It is possible that the new part turned out to be defective.
- New part installed incorrectly.
Here, perhaps, all the roots of the phenomenon are listed.
Let's talk about cost
Not everyone can afford this type of repair, like even reinstalling a sensor. Although the main difficulties are caused not so much by the replacement of one of the sensors involved in the process, but by the diagnosis of the sources of overestimation of the crankshaft speed when idling. After all, we found that the search for the causes of this disease is complicated by their diversity.
If the motorist decides to turn to the service station masters with a request to find the cause of the high engine speeds produced at idle, then the cost of diagnostics in large cities of the Russian Federation will be as follows.
| City | Price |
| Moscow | 700 rub. |
| St. Petersburg | 650 rub. |
| Ekaterinburg | 500 rub. |
| Samara | 500 rub. |
| Krasnodar | 550 rub. |
Since the price of manipulation is low, if the car owner doubts the success of his own diagnostics, he can safely contact the service station.
In the course of the article, we considered the main options for solving a common problem. Now, if a motorist encounters an over-idling idle speed, he will already know what to do.
Now read about and.