Floating engine speed in a field with an injector

You rarely see imported components on domestic cars. Basically, AvtoVAZ engines are equipped with a Solex or Ozone carburetor. Less often you can find products from the Dimitrovgrad Aggregate Plant, known for its reliability: the DAAZ carburetor. Drivers of relatively modern cars, accustomed to the check engine light, can easily determine any malfunction using an on-board computer or an inexpensive car scanner, but for veteran engine owners, only hardware diagnostics are available.

A common malfunction is idle speed floating, the main symptoms are:

It would seem that the problem does not affect the speed - with intensive use of the gas pedal, the malfunction is invisible. However, it is dangerous in traffic jams, when the engine may suddenly stall, and when engine braking on a long descent;
In addition, increased vibrations do not add life to the motor and attachments. Bearings of rotating shafts experience axial loads that are not typical for them. And it is uncomfortable for passengers to be in the car when the tachometer needle jumps from 500 to 1500 rpm.

The driver is forced to constantly apply gas, this distracts from the road and increases gas consumption.

So, manifestations of floating idle:

The tachometer needle moves smoothly or sharply in the range of 1000 revolutions;
The car shakes noticeably: there is always a feeling that it will stall;
Pops of unburned fuel in the muffler and under the hood. In the first case, the mixture is rich, in the second, it is lean;
Vibrations similar to tripping (at the same time you are sure that the spark plugs and the high-voltage part of the ignition system are in good condition);
The motor randomly picks up speed, then smoothly reduces it. The problem is non-linear, it suddenly appears and also disappears suddenly (this somewhat complicates the diagnosis).

It is not difficult to localize the fault. If (we repeat: in the absence of other malfunctions), the speed fluctuates, look at the carburetor.

Niva injector wandering idle speed reasons

Hello!
Tell. I bought a new Niva 2131, a five-door car, and drove it in good condition for 2000 km. And suddenly one day I refueled and after a while the car loses power and the fuel needle drops down. The car started to shake, the engine seemed to want to stall. The revolutions are sometimes below 900 per hundred, then higher at XX. We thought it was bad gasoline, but believe me, we have been struggling with this reason for half a year and have not found out, it turned out that it was not the engine or the fuel system, the spark plugs and the damper looked like new.

There is a small assumption if you let me know about the generator, there is nothing more to think about and there is nothing to check - everything has been replaced - sensors, diagnostics without errors. Why a generator, because that time when all this happened, along with the fuel needle, the charging dropped from 14 to 9, all at the same time. The cooling fans also started turning on late.

One mechanic fixed this for me - because the ground was missing, he ran wires from the negative terminal to the engine and charging appeared and the fans started working on time. But at the same time, for some reason, the starter began to turn very quickly - faster than even when it was working properly.

But the behavior with the car and the jolts did not help. I read one story about an Opel with this reason, it turned out to have a generator, the generator seemed to take energy from the engine, I’m not an expert so I’m not very good at electronics.

The same thing happens here, according to his description, the car plays revs at idle and while driving, and the charging repeats after it, when you accelerate, the revs go up and immediately down, to 700, charge 10, and then the revs level off. 900, charge 14.

Also when starting, sometimes it catches right away, and sometimes it will turn quickly, but won’t catch until you give it gas, and this is with a new battery and car. If it spins quickly, it's not the battery. All this behavior occurs in exchange or when the car is shaken, when it drives well, and when it starts to struggle.

Tell me, maybe the generator is ruining everything, or it has nothing to do with it, the mass is cleared everywhere. I will be very grateful.

Carburetor repair for dips and jerks

Carburetor repair may be necessary if the engine idles unstable, and adjusting the quantity and quality screws does not always help. Often the reason lies in over-enrichment of the mixture, which may be a consequence of incorrect adjustment of the float system or malfunctions in the vacuum economizer system for power modes. In the latter case, a torn diaphragm may need to be replaced or the economizer valve through which fuel is leaking may need to be repaired.

Model 2121 may cause jerking, swaying or dips when moving. In this case, there may be several reasons for their occurrence, which may require carburetor repair to eliminate them. Dips that appear when the throttle valve is slowly opened are often associated with clogging of the idle jet. Here it is necessary to adjust the fuel level and check the level of clogging in the main fuel jets.

If the car gives a deep failure when trying to open the first or second throttle chambers, then in addition to clogged nozzles, the reason may be poor installation of small diffusers in the corresponding sockets.

When the Niva 21213 gives slight twitches at low and medium speeds and accelerates sluggishly, it may be due to poor fuel dosage on the shut-off valve side due to its wear. In this case, repairs are needed in terms of replacing the shut-off valve with a shut-off needle made of metal with a valve that has this needle made of a different material.

Cars of the 2121 series sometimes give failures when any sudden opening of the throttle valves, which then disappear within 5 seconds when the engine is running at the same pace. Often such problems are associated with a malfunction of the accelerator pump, which leads to a lack of or an incorrect drop in gasoline flows. A similar situation can result from a diaphragm rupture, a rubber O-ring on the sprayer holder being destroyed, or the lower part of the valve being destroyed.

The main reasons why the idle speed of the VAZ 21214 floats

The question of why the idle speed is floating is perhaps the most frequently asked question regarding the engine. Indeed, problems with idle are a common occurrence that car owners have to deal with.

The most unpleasant thing is not that this is very serious or that repairs will be too expensive and time-consuming, but that there can be a lot of reasons why the idle speed is floating. In this article I will try to help you find and eliminate the cause of unstable engine speed, so that you save your time and nerves.

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Chevrolet Niva does not hold idle speed and stalls | Chevrolet

Why the Niva does not idle and stalls: the main reasons

The most difficult situation is braking down a hill. You need both brake and gas at the same time. Avoid such places. And so, you can fix it on the road.

The throttle position sensor does not keep the idle speed of the Chevrolet Niva 2. If your speed fluctuates while driving, and when you release the gas, the needle is in no hurry to return to normal speed, or it starts to move up and down, and this makes you ashamed to stand at a traffic light, because everything they think that you are a brainless shnivogonnik, accelerating from the traffic light and rushing. Then your problem is most likely in the throttle position sensor.

Both sensors are available for replacement.

How to adjust the carburetor on a VAZ Niva car

How does the Ozone carburetor work on the Niva 21213 and 2121, as well as other classic cars of the VAZ family? From the fuel tank, gasoline enters the float chamber in the appropriate quantity. Next, passing through the nozzle, the atomizer in the diffuser, the fuel is mixed with air. After this, depending on the degree of opening of the throttle valve, a certain amount of the air-fuel mixture is supplied through the intake manifold to the engine cylinder.

Adjustment of the Niva 21213 carburetor is resorted to in cases where it has been repaired, disassembled/cleaned, and when starting the engine is difficult or its operation is unstable. Some types of adjustments can be made without removing the unit from the machine, but in some cases, for example, when you need to adjust the starting device, dismantling is indispensable.

Throttle Actuator Settings

The main goal of adjusting the VAZ-21213 carburetor by adjusting its drive is to ensure the optimal throttle position for the extreme positions of the gas pedal. So, when the pedal is pressed all the way, the throttle should open completely and, conversely, as soon as you release the gas, it should close. This is achieved by setting the required rod length. To perform the adjustment correctly, follow the steps below:

Disconnect the drive rod from the bracket located on the cylinder head valve cover.
Using a key set to “8”, loosen the lock nut and, by tightening/unscrewing the rod end, set the optimal throttle position.
Now all that remains is to tighten the locknut and install the rod in its place.

Upon completion of the adjustment operations, it is necessary to make sure that the position of the damper actually corresponds to the position of the accelerator pedal. If the desired result is not achieved, repeat the described operations.

We are looking for the reason why the idle speed on the VAZ 21214 floats

Among other things, check the condition of the air filter; it may need to be replaced. Make sure that the ignition system is working properly and that there are no air leaks.

If the tips and recommendations described above do not produce results or you are not sure that you can cope with such work, seek help from professionals; specialists will quickly and accurately determine the source of the malfunction and stabilize the floating idle speed of the engine.

Thank you for your attention, I will be glad if it helps someone. If you know other reasons or methods of verification, you can safely add to this article using the comment form. Until we meet again, take care of yourself and your car.

If you find an error, please select a piece of text and press Ctrl+Enter.

I turned off the supply of crankcase gases going to the throttle to the throttle and everything seemed to be back to normal.

The engine does not hold idle speed well or stalls. The injector

Naturally, this takes into account external factors - speed, engine speed, temperature - and specified restrictions on the composition of exhaust gases. Also, the revs may fluctuate due to the vacuum tank, but most likely this is not the case. The same effect can be achieved by simply pressing the pedal for most of its travel.

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The idle speed fluctuates and the engine does not run stably. what is the reason? Change sensor XX...

I start it up, it runs smoothly, but if I go for a drive, it starts to glitch, the speed stays and doesn’t drop until you turn it off and start it again. It is only important to remember that any node has its own resource, which exhausts itself over time.

Carburetors

Car enthusiasts with extensive driving experience know firsthand about the device, which has entered into a well-deserved retirement thanks to the development of alternative methods of supplying fuel to the engine.
The carburetor has rightfully earned its recognition for its reliability. It was used both in the construction of amateur car models and in the field of motorsports. For trouble-free operation, it certainly requires attention. At the end of the 1980s, the world's major automakers gradually began to abandon this unit; in our country this happened a little later. Even such a well-known enterprise as the National Association of Stock Car Racing (NASCAR) not very long ago announced that it was also moving from mechanics to injection.

Carburetor is an element of the engine power supply system that meters and supplies the combustible mixture. To put it simply, it mixes fuel with air and directs it into the cylinders.

The device has special screws for adjusting the speed. The smoothness of operation depends on the mixture that enters the internal combustion engine. The car accelerates due to the operation of the throttle, the mixture passes through the accelerator pump. The most important thing is to adjust the unit correctly, but this is not easy, too little hot - bad, it won’t start. Too much is also bad, it will flood the candles.

Uninterrupted operation requires systematic adjustments. Changes in air temperature and pressure outside, the level of the float are a small part of the variables that affect the quality of the fuel, and its volume depends on the diameter of the nozzles. The composition can be adjusted manually. Many fans of fast driving, and even those who don’t particularly like to drive, are familiar with the tuning process.

The character of the engine directly depends on the carburetor settings. Even if you install the coolest spare parts, you won’t be able to experience truly great joy without a perfectly tuned device. The power unit will immediately respond when you press the pedal and rush off with all its power.

A slightly rich mixture will add power to the engine, but if you overdo it a little, the spark plugs will flood. Conversely, a lean mixture will reduce torque, and the likelihood of detonation will increase.

It starts poorly, the revs fluctuate at idle, when you press the gas pedal it stalls and black smoke comes out. All this indicates that this node is not configured correctly.

How to adjust correctly?

To avoid all of the above problems, just adjust the settings. This is done very simply, using a screwdriver we change the opening moment of the jets. A new factory carburetor is sold fully configured; for production cars, parameters are usually set for lower gas mileage.

The amount of air passing directly depends on the diameter of the diffuser. Accordingly, the more air, the higher the power. The main task: instant response of the car to throttle operation.

Without going into details, electronic injection is much more efficient than mechanical injection. Since the composition of the mixture is determined by the ECU (brains), I base it on the readings of various sensors. And the carburetor needs to be constantly reconfigured to suit environmental conditions. The composition of the fuel is affected by pressure, humidity and temperature.

This page presents original carburetors produced by the Dimitrovgrad Automotive Unit Plant, all of them have been tested and are completely ready for installation.

We carry out the adjustment ourselves

Niva 21213 can be subject to adjustment of the starting system by the gap at the edges of the valves, if the carburetor is removed, or by the crankshaft speed directly on the car. In the first case, the gap at the location of the lower edge (in the direction of air movement) from the throttle valve is set to a width of 1.1 mm. It is adjusted with a screw that has a 0.7 cm hexagon on the head and a slot from the shank. This operation is carried out with the cam lever turned counterclockwise from the starting system control (all the way). In the same position, the gap at the lower edge of the air damper is set to 3 mm using a screw in the cover from the diaphragm mechanism in the starting system (you need to loosen the lock nut). At the same time, the rod from the diaphragm must be forcibly recessed completely into the adjusting screw. After adjustment, the screw is fixed with a locknut.

What does carburetor adjustment include?

Adjusting the carburetor on Niva 21213 will allow you to achieve stable operation of this unit even at low speeds, when the crankshaft rotates at a minimum frequency.

As a rule, such work includes adjusting the starting system, idle speed, and the fuel level in the float chamber.

Before you begin the adjustment, you should prepare for this process. You will need a tachometer or multimeter with the appropriate mode, as well as a slotted screwdriver with a width of 3 mm.

Adjusting the VAZ 21213 carburetor is carried out in several stages:

If the engine is cold, it is necessary to warm it up - the temperature should be at least 85 degrees;
You need to fully open the carburetor air damper - to do this, press the damper drive handle, which is also called the “choke”, all the way.
Connect the tachometer to the stopped engine according to the following diagram: “minus” - to ground, “plus” - to terminal “K” on the ignition coil;
After connecting the device, start the engine, turn on the heater and headlights;
Take a screwdriver and, by adjusting the fuel mixture supply screw, ensure that the engine runs stably at idle speed. You can do this by ear, but it is better to use a tachometer that is connected to the engine. For a Solex carburetor, 750-800 rpm is optimal;
Unscrew the screw with a screwdriver until the speed rises to 900, and then tighten it again to 800 rpm.

If adjusting the carburetor on Niva 21213 did not help achieve the desired results, then you will have to remove it and disassemble it, thoroughly cleaning all the parts.

Idling on a Chevrolet Niva

At the same time, the electronics takes into account a whole set of parameters: And in no case should you allow the vehicle to be operated with a part that has exhausted its service life. A universal device for diagnosing any car. In some Chevrolet Niva models, the idle speed may sometimes freeze when changing gears.

So, when the neutral is turned on, the speed does not drop below. The error must be looked for in the software of the car’s on-board computer.

And only flashing it in a specialized service can help. Do you still think that diagnosing a car is difficult? If you are reading these lines, it means you are interested in doing something in the car yourself and really saving money, because you already know that: Maybe someone has encountered such a problem.

I changed the throttle body and the throttle body and washed the throttle body. When moving in neutral, the revolutions do not drop, they stay in the area. You stop and the revolutions drop to When the fan is turned on, the revolutions also drop. Diagnostics show everything is normal. Did you put the throttle cable exactly in place?: It throttles on its own, yeah.

I had a Kalina - in Maymax there is such a street of Yunosti, a private sector, I drove along it with the clutch half depressed, the Kalina rows slowly, but I let the clutch slip and it digs, and so it goes, in general there are only meters of road there, well I dropped off the passenger and drove back half-stressed.

Read more: Changing the oil in a Skoda Fabia gearbox

About 10 minutes later, I drove halfway and the clutch began to smell sharply. I turned it off, started it up five minutes later and drove off - I pressed the speed a little and immediately went higher, but the wheels didn’t move, somehow I got out of that damn road at those speeds.

Then the asphalt, acceleration - the revs also go up, but the car does not accelerate. I stopped on the side of the road to smoke and think about the situation. After about 10 minutes I start it up and the car drives as if nothing had happened.

This is exactly the same situation that happened a couple of weeks ago. I sinned on the IAC, but why does the speed only hold when coasting, and when stopping it returns to normal? I read somewhere that this kind of bullshit can also come from him. As a result, I bought a new IAC - it’s easier to replace.

I changed it, the problem did not go away. I reset the battery terminal again. But yesterday I went to the car market to buy oil and thought about buying a speed sensor at the same time. This morning everything is fine too. Also, the revs may fluctuate due to the vacuum tank, but most likely this is not the case.

I changed the DMRV and the result was 0.

I changed the speed sensor 0. I turned off the supply of crankcase gases going to the throttle to the throttle and everything seemed to be back to normal. The engine needs to be repaired with excess crankcase gases directly to the bulkhead. How old is the ShNiv, how long is the mileage? Diversant old air flow sensor was covered in oil inside!? Today, at a friend’s house, I looked at how the crankcase gases from the absorber are approaching the throttle in the opposite direction.

Unstable idling niva chevrolet

To do this, you need to completely remove the throttle assembly and either replace it if damaged or clean it using special products. In this case, some models will require additional computer diagnostics.

This component most often fails because it is constantly exposed to high temperatures. Therefore, in some cases it is better to start looking for problems there. It is also checked using a multimeter. After replacement, the ECU may need to be cleaned for errors.

The collector itself may also fail if the car has a sufficiently long service life. But more often the gasket fails. In this case, excess air is sucked in.

The speed in the field 21214 injector floats

Good day to all!
A small problem appeared: the idle speed began to float, somewhere in the range of 1000 - 1200 revolutions. I started looking for the reason. First of all, I tightened all the clamps of the pipes suitable for the throttle block to prevent air leaks. It didn’t help. I replaced the idle speed sensor, and since I had to remove the throttle unit, I washed it thoroughly with ABRO carburetor cleaner. But this also did not solve the problem. I decided to change the throttle position sensor. From the factory, the car had a TPS from the Arzamas manufacturer RICOR. I've already driven 78,000 km. Not bad for this sensor. I decided to install a contactless sensor produced in KALUGA. ALL! The problem has disappeared. The motor worked like new. I read about this sensor on the Internet. People praise. The plant guarantees 250,000 km. I also liked the work of the sensor. The idle speed is stable. The idle speed sensor (also manufactured in Kaluga) costs 690 rubles. Throttle position sensor (TPS) -810 rub. Total 1500 rub.

Name: Yaroslav Reg.: 03/21/2012 Threads / Messages: 3 / 8260 From: Taganrog Age: 28 Car: VAZ-21214-50-120 (06/01/2012), SHTAT UniComp 400L (firmware 3.3.1), VAZ-11173 2012, VAZ-21112 2006

Reg.: 03/05/2009 Messages: 22 From: Sevastopol Age: 40 Car: 21214, 2008

Reg.: 12/06/2004 Threads / Messages: 4031 / 23190 From: Moscow Age: 65 Car: 21214M, 2013

If the throttle valve cable is not tensioned at xx (check!), then the IAC is most likely to blame.

But the check does not light up for all errors - set the BC and look at the error codes. Without this, you still won’t figure it out and will wonder what other sensor to replace. As a result, saving on bookmakers will backfire.

Alexey aka ALER.

Reg.: 03/05/2009 Messages: 22 From: Sevastopol Age: 40 Car: 21214, 2008

Reg.: 05/05/2013 Messages: 102 From: Tambov Age: 49 Car: VAZ 21214 2007

Reg.: 04/15/2014 Messages: 6 From: Moscow Age: 36 Car: 21214, 1.7i, 2002 Euro-2

Good afternoon. This is the first time I’ve asked for help on a topic; before this I figured it out myself - thanks to the forum. I have been driving the field for 4 years now, and for all 4 years in cold weather (sometimes) after a long drive the idle drops after releasing the gas. Not step by step, but sharply almost to zero, sometimes it stalled. I was guilty of frosting the remote control, cleaning always helped or improved the situation, but when in warm weather my speed began to drop to 500 or less and the consumption subjectively increased to 16 liters in the city, I decided to put the squeeze on the problem. I drove around with the recreation center turned off, it seems everything is the same, although it’s difficult to judge. IAC, of course, also changed more than once, I don’t think it’s him. What annoys me is that I drove the car 60,000 km (155 thousand km mileage), I changed the DC when I bought it - the old one almost burned my car. But the mass air flow sensor still stands and how long it took me to get there is unknown. The voltage on it is 1.04V when igniting, it seems like it’s time to replace it, but for some reason I don’t believe that it’s throttling the revs. An important point - my DC knew the taste of antifreeze - the gasket broke in the cylinder, drove like a locomotive for six months, then capital, which means he also grabbed oil during break-in. How does it even work after that? The catalytic converter is knocked out, the compression was 11 11 10.5 11 last time. There is enough power, the only question is the idle failure after a long load. You can, of course, change everything at random, but the budget is limited. Came in today with a laptop and took “cardiograms”. It feels like DK has become lazy and has started to freeze. Can anyone estimate the DK sine wave? There are 3 pictures here – XX, 3 thousand. rpm, reset from 3 thousand. to XX. Here at the reset there is a suspicion that the DC is leaning the mixture. I don’t rule out leakage, I haven’t checked it yet, I’d like to hear advice from like-minded people. PS Sorry for writing a lot, but the whole picture is visible. Change the DC valve and/or mass air flow sensor? PPS I love my car - I won’t sell it to anyone))) Thank you!

Idle: (Air flow – 12-14kg/hour)

3000 rpm: Reset from 3000 rpm. to xx:

Pensioner

Specialist

We brought this device in today for diagnosis with the complaint “the engine runs in waves” I.e. The tachometer is in place, but there is uneven rotation. First of all, new spark plugs, wires, and checked the compression. Everything is okay. I didn't find any air leaks. I took out the forces, did the balancing - everything is ok here too.

According to the scanner, the readings: after starting everything is as if it were in the textbook, as soon as the lambda starts working and the SOP immediately begins to change in waves: from -20 to 5 degrees. pkv.

Factory firmware B120ER19

In which direction should I pick?

Sergo33

Guest

Expert

Rakso

Oscar

There was a similar case, but the sausage at XX (as if you were riding on a tram) began exactly at 90g.

after the fan was activated, it stopped for a couple of minutes.

Uoz also jumped, up to -19 degrees.

everything was checked, just like the pensioner

. rrx put a new one - the same eggs.

I noticed that if you raise the speed to 1000 or reduce the px steps to 28-30, everything returns to normal.

I consulted with some forum members and decided that it was hydraulics.

I'm not a mechanic and I didn't want to do anything with the engine, because... I was going to sell the stroller.

did it at about 1000 rpm. then I talked to Pasha - he sent me some medicine - the rpm is 800 and it doesn’t wobble))

To do this, the engine warms up to operating temperature. Then just check the sensor using a multimeter. If it malfunctions, you must replace it with a new one.

This component is responsible for the amount of air mixture entering the engine combustion chamber. If the sensor is not configured correctly, the fuel supersaturated with air will detonate more strongly, spinning the engine faster and increasing speed. The sensor can also be checked using a multimeter.

Chevrolet Niva does not hold idle speed and stalls

You just need to wait until the engine cools down so as not to burn your hands. The replacement itself is simple, unscrew the old one and screw on the new one.

The electrical connector there is such that you can’t connect it crookedly. When you first start the engine, the speed usually goes up. But, if you turn it off and start it again, the engine will work properly. Of course, there are other reasons for unstable engine operation, but finding problems there is more difficult. In any case, it is better to replace the sensors first. Basically, the problem here lies in a clogged throttle valve.

Factors influencing floating speed

When you turn on the car, the engine warms up quickly to reach the optimal temperature . After which, using the electronic control unit, the speed is reduced to normal values. When for some reason the unit does not work, you need to find out the cause of the malfunction.

Increased intensity of engine operation leads to disastrous results - thermal shock, malfunction in the cylinder block, accelerated depreciation.

When the idle speed fluctuates in a Chevrolet Niva with an injector, the reasons may be as follows :

Another possible problem is a malfunction in the electronic control unit.

Engine temperature sensor

If the device breaks down, the dashboard provides incorrect data regarding the engine temperature. To check and change the temperature sensor, proceed according to the following algorithm :

Prepare an autothermometer for working with high temperatures, a tester and a metal basin with water for heating on the stove.
Disconnect the connectors and, substituting the basin, remove the sensor from the socket. A plug is placed in place of the sensor.
The device is placed in cold water with the side screwed into the cylinder head. Measure the resistance and put the basin on the gas.
Measurements are taken several times at different temperatures and compared with the standard data in the service book.

Significant discrepancies indicate the need to replace the temperature sensor with a new one.

We are looking for the reason why the idle speed on the VAZ 21214 floats

Among other things, check the condition of the air filter; it may need to be replaced. Make sure that the ignition system is working properly and that there are no air leaks.

Didn't find the information you are looking for? on our forum.

Diagnostics of DXX

Often, problems with the idle air control valve are confused with a breakdown of the throttle position sensor . A distinctive feature is that the “Check Engine” indicator on the dashboard lights up in the event of a failure of the throttle position sensor.

The following signs indicate a breakdown of the idle air regulator::

If at least one point matches, it is necessary to check the DXX.

To check the functionality, measure the voltage supplied to the regulator :

If the regulator is faulty, it is replaced with a new one.:

The new device is assembled in the reverse order.

Troubleshooting Methods

You can solve problems with jumps and floating speeds yourself:

To confirm and eliminate the possibility of air leaks from the outside, check the supply system for leaks. Using a compressor or pump, supply air to the removed hose placed in water. This allows cracks to be detected.
The resistance of the IAC is measured. Values within 40-80 Ohms indicate that the device is not working.
During the diagnostic process, the crankcase gas ventilation valve is cleaned. It is removed and washed with kerosene or carburetor cleaner.
When sensors fail, they are not repaired, but replaced immediately.
If the throttle valve requires washing and removal, it is recommended to entrust the job to a specialist. Without removing the damper, you can wash the part yourself using a cleaning aerosol.
Adjust the idle speed by setting the “quantity” and “quality” screws on the carburetor. Clean the nozzle with an aerosol and blow it out with compressed air.

Important! All conductive contacts are disconnected from the throttle valve. In case of heavy contamination, after cleaning, set the required gap.

In most cases, eliminating these causes helps to get rid of floating speed.

Idling on a Chevrolet Niva

So, when the neutral is turned on, the speed does not drop below. The error must be looked for in the software of the car’s on-board computer.

Problems with throttle travel

These problems are similar to the breakdown of the TPS and entail the same consequences . A distinctive feature is that the problem is not in the electronic part, but in the degree of contamination of the part itself with oil vapors, waste combustion products, or due to the long-standing replacement of the air filter. If contamination is detected, the throttle assembly is removed and cleaned using special cleaners or replaced if damage is found.

Attention! After cleaning, the DS angle is often set incorrectly due to a “memory effect” in the electronic control unit. In such a situation, some models require additional computer diagnostics.

Why does the Chevrolet Niva experience increased idle speed on a warm engine?

All car enthusiasts sometimes face such a problem as high idle speed. But, unfortunately, it takes a beginner a significant amount of time to find and fix this problem without visiting a specialized car service center. To do this, you will need a detailed manual that will specifically describe all the necessary actions.

Main reasons

When starting, the engine can reach higher speeds to warm up faster. This manifests itself especially often in winter. But after some time, after reaching the minimum operating temperature, the electronic control unit is activated, which reduces the engine speed to normal. If this does not happen, then it is urgent to look for the reasons causing this problem.

Higher speeds indicate more intense engine operation, which can lead to a wide variety of consequences. Long-term operation may cause the engine temperature to rise significantly, resulting in thermal shock. This will cause problems in the operation of the cylinder block. In addition, most components will experience heavy wear and tear due to unstable engine operation and, as a result, accelerated wear. All this will affect the service life of the engine.

Therefore, it is necessary to immediately figure out what reason caused the increase in speed. There are several of them:

Ways to solve problems

Diagnosing this problem requires some knowledge as the process can cause irreparable damage to the engine. Therefore, you must carefully read the operating instructions for this car. It is also important to remember that Chevrolet Niva cars are equipped with injection-type gasoline engines, so increased idle speed on a warm engine is most likely caused by the electronic components of the car.

Checking the idle speed sensor

To do this, the engine warms up to operating temperature. Then just check the sensor using a multimeter. If it malfunctions, you must replace it with a new one.

Throttle position sensor

Problems with throttle valve travel.

These problems are similar to the failure of the throttle sensor and lead to the same consequences. Only the main problem here is not electronic - but contamination of the damper itself by oil vapors coming from the crankcase, combustion residues, or due to rare changes of the air filter. If there are traces of contamination, the damper must be cleaned. To do this, you need to completely remove the throttle assembly and either replace it if damaged or clean it using special products. It is important to remember that after cleaning, the throttle valve angle may be incorrectly set due to the so-called “memory effect” in the ECU. In this case, some models will require additional computer diagnostics.

Engine temperature sensor.

Damage to the intake manifold.

The collector itself may also fail if the car has a sufficiently long service life. But more often the gasket fails. In this case, excess air is sucked in. To fix the problem, it is necessary to dismantle this part, as well as the units on which the injection elements are located. Before installing the gasket, it is necessary to thoroughly sand the surface of the manifold and clean it of traces of the old gasket. But it is important to remember that the occurrence of this problem is accompanied not only by increased idle speed. Damage to the gasket makes it difficult to start the engine and the speed fluctuates while driving.

As can be seen from practice, there are a very large number of problems that can cause increased idle speed on a warm engine. Therefore, if there are doubts that self-repair will not bring the desired result, it is better to entrust the car to specialists who, with the help of professional equipment, will be able to quickly identify the defect and eliminate it.

Why the speed fluctuates - localization of the fault

First, you need to cut off potential sources of the problem close to the carburetor.

Let's leave the fuel supply alone. It (gasoline) is either there and the engine is running, or it is not there and there is no problem with idling (as well as the engine itself);
A potential culprit is a clogged engine air filter. The main cause of uneven idle is air, or rather oxygen, so we inspect the first obstacle in the way of oxygen especially carefully. If you changed the filter at the end of spring, it may be clogged with June poplar fluff. Regular trips on primers, or clouds of dust donated by the “coaters”, coke the pores of the filter element within a month. It happens that a low-quality product from “homemade” ones from the Middle Kingdom simply breaks into shreds and clogs the carburetor throttle assembly with scraps. In any case, let's start by checking the filter;
The diametrically opposite reason is excess oxygen. The intake tract of an internal combustion engine is relatively sealed. All incoming air flows are carefully calculated by engineers. In injection systems there is a mass air flow sensor, and the ECU can adjust the mixture parameters depending on the oxygen flow. The carburetor has only a mechanical setting for a certain volume. Any unauthorized air leak causes floating speed. The filter breaks, the valve cover gasket breaks, or the carburetor seal leaks - and unaccounted for (and also dirty) air goes into the chamber. The leak can be on the fittings of the vacuum tubes and on the crankcase ventilation system.

A less common cause is the housing or diaphragm of the distributor vacuum regulator. That is, the device responsible for the stable operation of the power unit is itself the cause of the malfunction.

If none of the listed reasons are found, we will inspect the carburetor. Moreover, no special equipment, much less electronic devices, is required.