VAZ 2114 injector idle speed fluctuates - reasons

List of main reasons

Reasons why idle speed fluctuates

Incorrect operation of the power unit may be caused by a malfunction of certain elements:

• Failure of sensors:

1. RXX;
2. DMRV;
3. DPKV;
4. Lambda probe;
5. DSA.

• The XX solenoid valve is faulty;
• The air filter is clogged;
• Heavy carbon deposits on candles;
• High-voltage wires are damaged or oxidized;
• Air leak in the intake manifold;
• Incorrect throttle position.

Do-it-yourself troubleshooting

Many faults from the above list can be eliminated yourself in a few minutes. It will take much more time to identify.

Diagnostics of mass air flow sensor and IAC

The mass air flow sensor and idle air control act as regulators of air supply to the combustion chamber.

Failure of these sensors will lead to an increase in fuel consumption, and a broken rod will affect the speedometer needle; it will remain motionless until the problem is fixed.

Diagnosis of DPCV

Crankshaft rotation sensor location

Failure of the crankshaft position sensor will negatively affect the operation of the engine as a whole. A failure in synchronization between the engine and the injection system will result in the car not starting. You can accurately determine the condition of the sensor only by using a multimeter.

To do this you need to do the following:

• Set the position on the sensor with a maximum value of 200mV;
• Connect the multimeter and close the core with a screwdriver;

Checking DPKV with a multimeter

Video about checking the crankshaft rotation sensor

Lambda probe diagnostics

Location of the oxygen sensor (lambda probe)

The sensor reads the amount of oxygen in the exhaust gases and sends a signal to the computer to increase or decrease the air supply to the combustion chamber. Diagnostics is performed with a multimeter on a warm engine. The procedure is as follows:

• One core of the device clings to the ground, the second to the output from the sensor;
• When re-gassing the engine, the multimeter readings should be in the range from 0.2 to 0.9 V;

When checking the lambda probe, the voltage readings should be within 0.2 - 0.9V

Video about checking the lambda probe

Speed ​​sensor diagnostics

The vehicle speed sensor is located in the gearbox. Its diagnosis is carried out by visual inspection of wires and contacts . If oxide is detected, it must be thoroughly cleaned.

Replacing the air filter and glow plugs

Air filter for VAZ-2114

The presence of a large amount of dust on the body and inside the air filter requires its immediate replacement.

Since its throughput is reduced, the engine does not have enough air in the combustion chambers . Due to this, the fuel does not burn completely, and the remaining fuel is thrown out and burns out in the exhaust pipe, which can burn out as a result.

Air flow sensor

If the IAC turns out to be serviceable, then you should check the air flow sensor. To do this, you will also need a multimeter set to voltage measurement mode (in the range of up to 20 volts).

Measurements are carried out as follows:

• turn off the engine and turn on the ignition;
• measure the voltage at the sockets used to connect the yellow and green wires;
• if the voltage value is in the range of 0.98 - 1.02 volts, then the sensor is working. If not, then action should be taken.

DMRV VAZ 2114

To begin with, you can try to clean the sensor by blowing it with a composition for cleaning carburetors (in the form of an aerosol), although this does not always help. If after purging the voltage readings return to normal, then the “repair” was successful; if not, then the sensor will have to be replaced with a new, similar one.

Video about problems with idle speed on a VAZ-2114, computer diagnostics

• Reasons for floating idle speed on Lada Samara
• What causes unstable engine operation?
• We are looking for the cause in the sensors
• Mass air flow sensor
• Crankshaft sensor
• Throttle position sensor
• Idle air control sensor
• Checking the idle air solenoid valve
• Checking spark plugs and ignition system

Does the idle speed of the VAZ 2114 (injector) float and the reason is unclear? Don't put off fixing the problem too long. Diagnostics and repairs will not take up a lot of your time and money, but can prevent more serious consequences.

Conclusion

Many car enthusiasts do not know the reasons for the high idle speed effect, much less how to eliminate it. So, of course, experts and car mechanics recommend contacting a car service straight away, but our man won’t stop until he tries it himself.

There are many reasons for the effect of increased speed, from faulty sensors to errors in the electronic control unit. You can also fix the problem at home, which is what owners of VAZs and other domestic cars do. But owners of foreign cars will have to contact a car service center, where repairs can amount to a considerable amount.

Good afternoon. Help with advice. In general, in the cold weather the check light came on. At first the speed just started to jump a little. Now the idle is kept at 1.5k almost all the time. And if you press the clutch at speed, it increases up to 3k. From time to time the check does not disappear for long, but the problem does not go away, you have to revise the throttle all the time so that the speed drops. Also, all this is accompanied by increased gasoline consumption. Unfortunately, there is no BC, and I consider it a waste of money to go for diagnostics; they rarely help anyone significantly.

After reading a lot of posts about this, I realized that it was necessary to sin on one of the following: IAC, DMRV, DPS or lambda probe.

But I changed the pxx recently, when the speed, on the contrary, dropped to 0.5, plus if there are problems with the pxx, the check light does not light up.

The main task of the idle speed system (mode) is to maintain engine speed at a minimum level, ensuring complete combustion of the fuel-air mixture in the cylinders. The number of idle speeds on different engines may vary, the range is 700-950 rpm. Excessively low tachometer readings lead to unstable engine operation, which may stall. On the other hand, high engine speeds at idle are fraught with excessive fuel consumption and more toxic exhaust. Below we discuss the main reasons for the increased and unstable crankshaft speed at idle for a carburetor and injection engine.

Sources

• https://carfrance.ru/pochemu-vaz-2114-plavayut-oboroty-na-xolostom-xodu/
• https://luxvaz.ru/vaz-2114/135-plavayut-oboroty-na-holostom-hodu.html
• https://mashinaa.ru/avtovaz/vaz-2114/6444-plavajut-oboroty-na-holostom-hodu-vaz-2114-inzhektor-prichiny.html
• https://remontvazov.com/plavayut-oboroty-na-holostom-hodu-vaz-2114-inzhektor
• https://FB.ru/article/146420/plavayut-oborotyi-na-vaz—-prichinyi-i-metodyi-ustraneniya
• https://provaz2114.ru/dvigatel/plavayut-oboroty-na-holostom-hodu-vaz-2114-prichiny.html
• https://pol-z.ru/plavayut-oborotyi-na-holostom-hodu-vaz/
• https://prometey96.ru/ustrojstvo/plavayut-oboroty-vaz-2114.html

Checking the idle air solenoid valve

The idle speed solenoid valve regulates the exhaust gases - some return to the combustion chamber. The toxicity of emissions is reduced.

To check the functionality of the valve you need to:

• disconnect the valve power cable;
• turn on the ignition;
• attach the power wire to the valve terminal - the valve should click. If there is no click, you can connect the contact with a wire to the “Plus” terminal of the battery. The absence of a click will indicate a valve malfunction.

Checking spark plugs and ignition system

If you have not found which sensor is responsible for the floating engine speed, you should pay attention to the condition of the spark plugs and high-voltage spark plug wires. The cause of the malfunction may be:

• carbon deposits and contamination of spark plugs. Cleaning can only provide short-term improvement. It is better to replace spark plugs with new ones;
• damage to wires. High-voltage spark plug wires are checked visually for damage (at night, if the insulation is damaged, a spark is noticeable when the engine is running).
• bad contact. You need to check the condition of the contact of the wires and spark plugs (disconnect and reconnect the spark plugs);

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Engine ECU

Very often the cause of this trouble is the “brain” of the car, that is, the electronic control unit. If any sensor responsible for the correct operation of the internal combustion engine breaks down, or if foreign air enters, the computer cannot give a specific and accurate command to the system, which leads to floating speed. In this case, you should go to a service center and diagnose the ECU, since it is unlikely that you can determine error codes and malfunctions on your own without special tools and devices.

Sensors and their malfunctions

Of course, if the ECU issues incorrect commands, this does not mean that it is faulty. The cause of breakdowns should be sought in the following sensors:

1. IAC (idle air regulator).
2. MAF (mass air flow sensor).
3. EGR.

It is because of these parts that the speed on the VAZ-2114 most often fluctuates.

If all these elements are working correctly, you should diagnose the spark plugs and check the condition of the air filter. By the way, sometimes the cause of floating speed is not the sensor itself, but its electrical wiring.

How does this happen

If the car is running normally, all you need to do is start it and wait until the engine warms up to the optimal temperature. The tachometer indicator at this moment is at 2-2.5 thousand rpm, and then gradually drops to about 800 rpm as the power unit warms up.

But when there are problems, the idle speed jumps and changes sharply. The range of revolutions difference on the tachometer can be significant, up to 1.5 thousand revolutions. The car seems to live its own life. After some time, this phenomenon stops. But the next time the ignition is turned on, everything repeats.

Why does the speed fluctuate on the VAZ-2114? Diagnosis of IAC

First of all, we check the IAC sensor. On domestically produced cars, it is installed on the throttle body near the throttle position sensor with two mounting screws. To check its performance, we need to prepare a multimeter. First, turn off the ignition, then disconnect the block with the wire from the sensor and, using our device, measure the resistance level between the contacts of the regulator. Under normal conditions, this value is 40-80 Ohms. If the readings you receive do not correspond to the norm, most likely the regulator has malfunctioned. In this case, it must be replaced.

Next in line to check is the mass air flow sensor.

Cleanliness of the damper assembly

The throttle valve assembly is diagnosed by visual inspection for contamination. Clean the part with cotton swabs and a toothbrush moistened with a cleaning solution. For ease of work, the device is dismantled. After cleaning, it is recommended to blow out all channels and pipes of the unit with compressed air using a tire inflator.

To clean the part, it must be dismantled.

Attention! It is recommended that the channel responsible for removing gases from the crankcase be completely filled with a cleaning solution before purging - the diameter of the element is very small and there is no other way to access it.

Why does the idle speed fluctuate on carburetor engines?

The VAZ-2114 Samara with a carburetor internal combustion engine is also not immune to this problem. This happens, fortunately, not every day, but still. The main reason for this is an incorrectly adjusted or faulty carburetor itself. Also, floating speed can be caused by air leaks or a faulty XX solenoid valve. In addition, it is worth checking the air filter for deposits.

But most often, floating speeds arise precisely because of incorrect carburetor adjustment. In this case, you should adjust it by correctly rotating the fuel quality and quantity screws.

As for the solenoid valve, it can be diagnosed without removing the power wire from it. With the ignition on, it is enough to touch the contact on the valve with the cord - a characteristic click should soon appear. If it is not there, you can try to touch the contact with the wire that is connected to the positive terminal on the battery. If after this you do not hear a click, then most likely the valve has malfunctioned. To repair it, you need to unscrew it and clean the nozzle.

So, we found out why the speed on the VAZ-2114 fluctuates and how to fix this problem depending on the type of fault.

Methods for eliminating floating engine speeds

When starting to find and eliminate the reasons that cause unstable operation of the engine in idle mode, you first need to check:

1. Condition of the air filter and spark plugs. If they become critically dirty, they need to be replaced.
2. Integrity of insulation of high-voltage wires. If damage is found, they must be replaced.

It is recommended to make sure that there is no suction at the junction of the intake manifold with the engine cylinders. To do this, with the engine running, you need to sequentially spray all joints at the joints with carburetor cleaner or other flammable liquid. If atmospheric air enters there, the car engine jerks sharply, which is why, if a damaged gasket or plug is detected, the element is replaced.

Checking the tightness of the intake manifold (video guide)

Let's consider the remaining elements of the car, the malfunction of which can affect the smooth operation of the VAZ 2114 engine in idle mode.

Solenoid valve diagnostics

Cars with engines equipped with a carburetor are equipped with idle speed solenoid valves. Devices are checked as follows:

1. Disconnect the power cord.
2. Start the engine to warm up.
3. Connect the wire. If a clear click is not heard, the part must be replaced.

Attention! To fully ensure that the valve is working properly, be sure to clean the nozzle and repeat the test.

Is the EGR system on the injector working?

"Floating" speed can be caused by jamming of the exhaust gas recirculation (EGR) valve, which is installed in the exhaust manifold. It is necessary to periodically remove dirt from the valve seat and its seat using a carburetor cleaning aerosol, avoiding liquid getting on the sensor diaphragm.