Adjusting the idle speed of a Chevrolet Niva

While the engine is idling, air is supplied to the engine using the idle speed regulator. This device is a two-pole stepper electric motor, with a cone valve connection. And when the ECU sends a signal to the regulator, it moves the valve, limiting the passage of air through the channel.

Please note that this device is non-separable, and when it fails it must be completely replaced; it is also worth noting that its dismantling must be done only after inspecting and removing the entire throttle assembly.

Adjusting the idle speed of a Chevrolet Niva

The idle air regulator is a special device that regulates the air supply.
It is made in the form of a cone-shaped valve, which is driven by an electric motor. The ECU is activated, which determines the required channel opening level. The Niva Chevrolet idle speed control is non-separable, therefore, if there are problems with its operation, it must be completely replaced. Dismantling is somewhat difficult, since to remove the regulator it is also necessary to disconnect the throttle assembly.

Procedure for removing the device.

To remove this device, you need to stock up on a small set of tools, consisting of a 13mm socket wrench, a screwdriver and pliers.

Place the vehicle on a flat surface and secure it with the parking brake. If there is any doubt about the stability of the car, you need to install wheel chocks.
After this, you need to disconnect the battery terminals.
We unscrew the fastening nuts and studs that secure the receiver to the throttle valve. In this case, there is no need to disconnect the pipes of the cooling and crankcase ventilation system.
Disconnect the terminals from the wires
Using a Phillips screwdriver, unscrew the valves on the throttle valve
When the device mount is unscrewed, you can remove it from its seat. Usually, you can get the O-ring along with it. But, in some cases, it may get stuck in the damper well.
In this case, it is necessary to carefully dismantle it.

But sometimes the device may be working properly, but problems in operation are associated with its clogging. In this case, you can try cleaning it with carburetor cleaner. Typically, this method helps to revive a device that has no visible mechanical damage. But this measure does not guarantee a 100% result, but is only temporary, which allows you to get to the nearest service station or store with spare parts.

The idle speed of the Chevrolet Niva may be incorrectly adjusted if the sensor has increased travel between the valve and the supporting surface. When measured with a caliper, this distance should not exceed 23 millimeters.

Compliance with these parameters is necessary in order to ensure correct installation and not damage the throttle body.

Before installation, the seat must be cleaned. You can also lubricate the O-ring with engine oil to make it easier to put it in place.

Throttle sensor.

The Niva Chevrolet throttle sensor can also affect the smooth operation of the engine at idle. This component controls the amount of air mixture that enters the cylinders. The main task of this part is to make this quantity optimal for high-quality ignition.

The Chevrolet Niva throttle valve is regulated by a special sensor, which, if necessary, closes it, forming a vacuum in the intake system, or opens it, allowing the air mixture to pass through.

If the TPS is faulty, then malfunctions occur during idling. In this case, you need to remove the element and carry out diagnostics.

1. First you need to disconnect the wire block to de-energize the sensor

2. To check its functionality, you need to use a multimeter to measure the voltage between the first and third connectors in the block. In this case, you need to move the damper position from closed to open.

3. The element itself is secured with 2 screws, which need to be unscrewed for replacement.

4. After removing the element, check whether there is an o-ring left in the seat. You need to check its appearance and if everything is in order, install it in place.

5. Now you can install the new part and reassemble in reverse order.

Replacing the rear brake wheel cylinder

If during operation there are traces of brake fluid leakage on the brake drum and the inside of the wheel, replace the working cylinder.

Repairing the working cylinder often does not lead to positive results, and this requires special tools. Therefore, it is recommended to replace the cylinder assembly.

You will need: a 10mm wrench and a special wrench for the brake pipe nuts.

1. Engage first gear and install support blocks under the front wheels.

2. Remove the corresponding wheel.

3. Clean the brake pipe mounting area and the brake cylinder mounting bolts on the back side of the brake shield from dirt. To make it easier to unscrew the cylinder mounting bolts and the brake pipe mounting nut, apply WD-40 to the threaded connections.

4. Remove the brake drum.

5. Raise the parking brake lever until the upper ends of the shoes come out of the piston grooves.

6. Unscrew the nut securing the brake pipe to the working cylinder and...

7. ...plug the hole in the tube, for example with the cap of the air release valve

Unscrew the two bolts securing the working cylinder, holding it on the other side, and remove the working cylinder

After long-term use, the brake pipe nut “grows together” with the pipe into one piece, and when you try to unscrew the nut, the pipe twists and breaks.

In this case, just move the tube nut a little, then unscrew the cylinder mounting bolts and disconnect it from the tube, unscrewing the cylinder from its nut.

After disconnecting the cylinder from the tube, the mobility of the freed nut can be restored by moistening it with brake fluid and turning the nut with a wrench alternately in both directions.

10. Install the slave cylinder in the reverse order of removal.

11. Bleed the brake system (only the working cylinder on the wheel being replaced is allowed).

12. Be sure to install the protective cap on the air release valve.

We check the idle speed sensor of the Chevrolet Niva. Replacement with a new one

Any breakdown in a car requires a timely solution, as it can lead to more serious problems.
Sensors in a modern car are one of the most important measuring devices. The failure of at least one of them leads to the fact that the ECU is not able to obtain a complete picture of the progress of the system.

Operating principle of the idle speed sensor.

The idle speed sensor, otherwise known as the regulator (IAC), allows you to select the optimal crankshaft speed depending on the specified conditions. If this part breaks down, the rhythm of the engine’s operation is disrupted, since a sufficient amount of air does not enter the combustion chamber, or a too lean mixture is formed, as a result of which the engine speed begins to float, this is especially noticeable at idle speed.

The principle of operation is as follows: the air mixture flow sensor (MAF) determines how much air has entered the combustion chamber, after which the electronics calculates how much fuel needs to be supplied to the injectors. The engine speed is read by the crankshaft sensor (CPS), and if this indicator is low, the IAC increases the air supply, simulating pressing the gas pedal. The system operates in the same way when starting from a cold state. The IAC increases the air supply so that the engine quickly warms up to the optimal temperature, or you can start driving without fear of stalling.

Where is the idle speed sensor located on a Chevrolet Niva.

On the Niva 2123, the idle speed control is made in the form of a small electric drive with a spring and a rod ending in the form of a needle, which are enclosed in one housing. The IAC is attached to the throttle body. The sensor starts working when the key is turned in the ignition switch. At this moment, the rod rests against a special hole to count the necessary steps, after which the valve returns to its original position.

Signs of malfunction.

Very often, an IAC malfunction can be confused with problems that arise when the throttle position sensor fails. The only difference is that if the TPS breaks down, the CHECK ENGINE indicator lights up on the instrument panel. If the IAC malfunctions, this indicator does not light up.

In addition, a malfunction of the regulator can be determined by several main signs:

When starting the engine, the speed will fluctuate greatly.
If you turn on the headlights or heater, the speed may drop below 500 rpm.
When starting the engine after a long period of inactivity, it does not go into warm-up mode, but operates at normal or low speed.

If one or more signs coincide, there is a need to check the regulator. Let's look at the main ways to check the sensor on a Chevrolet Niva:

To check its functionality, you can measure the voltage going to the regulator. Verification steps:

Place the car on a level surface and raise the parking brake lever.
Disconnect the terminals from the regulator.
We take a multimeter and connect the black wire (minus) to the motor housing, and connect the other wire (+) to connectors A and D alternately.
Turn the key in the ignition and watch the multimeter.
Normal voltage should be 12 Volts. If it is much less, there are problems with the battery charge.
If there is no voltage at all, there is a break in the circuit going to the IAC. In this case, it is necessary to check all the wires going to the sensor and the ECU.
When checking the resistance, it is necessary to test the IAC terminals one by one - A and B, C and D. If it is working, then the resistance should be 53 Ohms.
If you measure the resistance at terminals B and C, A and D, the readings will be higher than the critical values.
The procedure for replacing the idle air regulator on a Niva Chevrolet.

To carry out this procedure you will need a certain set of tools: a 13mm socket, a Phillips screwdriver and pliers. Then we proceed to dismantling:

Place the car on a flat surface and secure it with the parking brake.
Remove the negative terminal from the battery.
Unscrew the nuts on the throttle studs. In this case, it is not recommended to disconnect the canister and cooling system pipes.
Remove the terminals from the IAC.
Using a Phillips screwdriver, unscrew the screws that secure the sensor.
We take the device out of the seat.

Replacing rear brake pads

The minimum permissible thickness of the friction linings of brake pads is 1.5 mm.

Replace the pads in the following cases:

– the thickness of the friction linings is less than permissible;

– the surface of the linings is oily;

– the friction lining is not firmly connected to the base;

– the linings have deep grooves and chips.

Do not use gasoline, diesel fuel or any other mineral solvents to clean brakes.

Replace the brake pads on both rear wheels at the same time. It is not permissible to replace the front and rear pads with each other, as well as between the left and right wheels. This may result in uneven braking.

Also interesting: How to remove a brake drum on a Chevrolet Niva

You will need: pliers or a screwdriver, two mounting blades.

1. Engage first gear and install support blocks under the front wheels.

2. Check: the parking brake lever must be lowered all the way down (the car is released).

3. Remove the wheel.

4. If the brake fluid level in the master cylinder reservoir is at or near it, pump out some of the fluid from the reservoir. Otherwise, when replacing the pads, it may splash out.

5. Remove the brake drum.

6. Remove the lower tension spring with pliers

7. You can remove the spring with a screwdriver.

8. Rotate the upper cup of the pressure spring 90° and...

9. ...remove it together with the spring and the lower cup.

Remove the pressure spring rod from the brake shield.

10. Remove the second pressure spring in the same way.

11. Remove the pads assembled with the spacer bar and the upper spring

12. Move the lever away and disconnect the parking brake cable.

13. Hold one of the pads with your foot, stretch the spring and remove the spacer bar.

14. Remove the upper tension spring.

15. To replace the rear shoe, unpin the parking brake lever pin.

16. Remove the washer and lever

Remove your finger.

18. Install the removed parking brake drive parts onto the new brake pad in the reverse order of removal.

To prevent the parking brake drive from seizing, lubricate the working surface of the pin with a thin layer of grease.

19. Install the pads in the reverse order of removal.

After installing the pads, bring them together by pressing them with two mounting blades.

20. Install the brake drum.

21. Press the brake pedal several times to set the wheel cylinder pistons to their working position.

22. Reinstall the wheel. Check that it rotates easily.

23. Replace the brake pads of the other wheel in the same way.

24. After installing the brake pads, adjust the parking brake system (see “How to repair the handbrake on a Chevrolet Niva”).

This is interesting: Adjusting and replacing the Chevrolet Niva throttle cable

Idle speed regulator Niva, 2121/2123, Chevy

Introduction

The Niva car began to be produced during the Soviet Union and over time was subject to various modifications and improvements. So the carburetor engine was replaced by a more technologically advanced and advanced engine with fuel injection.

As a rule, for an engine to operate with an injector, a large number of different sensors are required, which automate and simplify the process of working with an internal combustion engine. In this article we will talk about one of the Niva’s sensors, namely the idle air control (IAC).

Description of IAC

The idle speed control was installed only on Nivas with fuel injection and a mechanical throttle. When installing an electronic throttle, IAC is not used, since the entire IAC process is controlled electronically.

The regulator is designed to regulate engine speed at idle by adjusting the air supplied to the cylinder head. The IAC is a DC motor with a worm gear on the shaft, which has a cone installed that regulates the air supply through the IAC channel in the throttle assembly.

This sensor is quite unreliable, often subject to breakdown and replacement. Due to its unreliability, it was subsequently abandoned in favor of an electronic throttle.

IAC device

The idle speed control is a DC motor. Below is a diagram describing the parts that make up the Niva IAC.

Movable air flow valve;
IAC fixing plane;
Winding;
Shaft with worm gear;
Output (connector);
Sleeve;
Frame;
Anchor;

Where is the sensor located

The Niva IAC is installed on the throttle assembly from its rear part and is secured with two screws, a Phillips screwdriver, to the body.

There is no such sensor on the electronic throttle (on a car with an electronic gas pedal).

Symptoms of a problem

The sensor is completely mechanical and if it breaks, the check engine warning light does not light up. A breakdown can be diagnosed only by the signs of an IAC malfunction, which are described below.

Signs:

Spontaneous engine stop at idle;
Stopping the engine when switching to neutral;
There are no warm-up speeds on a cold engine;
The revolutions are floating;
Spontaneous increase and decrease in speed at idle;

All these signs indicate IAC only when they are detected at idle, since the regulator operates in idle mode and does not participate in the operation of the internal combustion engine at high speeds.

Checking the IAC Niva

Checking this sensor to accurately identify its failure must be carried out in two ways: visual inspection and multitherm testing. Let's look at each of the checks in more detail.

Visual inspection

This check is carried out only after removing the IAC from the remote control.

It is necessary to check the condition of the regulator body; there should be no chips, cracks or gaps between the metal and plastic parts.

The presence of all rivets securing the plastic part of the sensor is checked, since the absence of a rivet may be accompanied by the passage of air.

Check the condition of the rubber sealing ring. There should be no burrs or cracks on it.

The mobility of the worm shaft is checked. He should move around without biting.

Check that there is no carbon deposits on the regulator cone.

Checking with a multimeter

Since the sensor is mechanical and, in principle, its design is based on a conventional DC motor, the test is carried out by measuring the resistance of the IAC winding.

To check on a multimeter, set the switch to measure a resistance of 200 ohms.

We connect the multimeter probes to the central terminals of the IAC and measure the resistance on them. The reading on the device screen should be close to 50 ohms. If the device shows 1 or infinity, then most likely a winding break has occurred.

If the winding breaks, the idle speed regulator VAZ 2121-2123 must be replaced with a new one.

Sensor cost

Manufacturer	vendor code	Price, (rubles)
LADA	2112114830002	990
AvtoVAZ	21120114830004	600
Standard	21120-1148300-81	680
Pegasus	2112-1148300-03	805
ERA	FJ480	370

Replacing the sensor

Replacing the idle speed regulator on a Niva is quite simple and easy. To complete this procedure without error and with ease, we recommend following the instructions below.

Visual inspection

This check is only performed after removing the IAC from the remote control.

It is necessary to check the condition of the regulator housing. There should be no nicks, cracks or gaps between metal and plastic parts.

The presence of all rivets securing the plastic part of the sensor is checked, since the absence of a rivet may accompany the passage of air.

Check the condition of the rubber o-ring. There should be no marks or cracks on it.

Chevrolet Niva idle speed control which is better

The most common causes of failure of the idle air regulator (IAC) 21203 - 1148300 on the Chevrolet Niva -2123, VAZ 2131 (NIVA) and VAZ - 2120 "Nadezhda" modifications.

Symptoms of IAC malfunctions are in many ways similar to TPS (throttle position sensor) malfunctions, but in the second case, most often the “CHECK ENGINE” lamp clearly indicates a TPS malfunction.

Malfunctions in the operation of the idle speed controller (IAC) 21203 - 1148300 are difficult to identify, because the idle speed sensor on the Chevrolet Niva - 2123, VAZ 2131 (NIVA) and VAZ - 2120 "Nadezhda" of their modification is an actuator and is not covered by a general control system, and if there is a malfunction in its operation, the “Check-Engine” indicator light does not signal.

But some characteristic symptoms suggest a malfunction of the idle speed sensor, for example:

— unstable idle speed;

— when setting the gearshift lever to the neutral position, the engine stops involuntarily;

— idle speed decreases noticeably when other devices (heater, headlights) are turned on;

— involuntary increase or decrease in speed, regardless of the engine operating mode;

— when a cold engine starts, difficulties arise in reaching higher speeds.

There are several ways to check the idle speed sensor on the Chevrolet Niva - 2123, VAZ 2131 (NIVA) and VAZ - 2120 "Nadezhda" modifications.

Let's look at some of them.

Checking the voltage going to the regulator.

— We put the car on the handbrake or install anti-roll bars so that it does not roll;

— Disconnect the sensor from the wire block;

— We check the presence of voltage with a conventional voltmeter: the negative probe is on the engine, the positive probe is on the terminals of the connecting block, wires A and D.

— Turn on the ignition and analyze the resulting measurements. The operating voltage must be at least 12 V. If it is less, there may be a problem with the battery charge.

— If there is no voltage (open circuit), we check the electronic control unit and the entire circuit.

— Circuit resistance measurement. We analyze terminals A and B, C and D one by one - a working sensor will produce 53 Ohms.

- We measure Ohms in pairs B and C, A and D - the resistance if the IAC operates correctly will be infinitely high.

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Any breakdown in a car requires a timely solution, as it can lead to more serious problems. Sensors in a modern car are one of the most important measuring devices.

The failure of at least one of them leads to the fact that the ECU is not able to obtain a complete picture of the progress of the system.

Operating principle of the idle speed sensor.

How does the replacement take place?

The design of the Chevrolet Niva engine allows for replacing the IAC without removing the throttle pipe . This is quite inconvenient, but possible.

Difficulties arise when unscrewing and replacing the rear regulator mounting screw . You have to work with a screwdriver at a certain angle. Therefore, you should not remove the screw after unscrewing; it is better to remove it together with the regulator. The same must be done when installing a new part: first place the screw in its hole and only then install the IAC in the damper body.

Important! We must remember that there is a sealing rubber ring. If, when dismantling a part, it remains in the socket, it must be removed. A new ring is included with the sensor. To avoid damaging it during installation, apply a few drops of clean motor oil to it.

The ability to simply replace the IAC without dismantling unnecessary parts does not mean that you always have to do just that . As a rule, the need for replacement arises after a significant mileage of the car, when the power system is already clogged with all sorts of foreign inclusions, and it is better to combine the work with flushing the throttle.

To do this, the throttle assembly is dismantled as an assembly , after which it is much easier to replace the faulty IAC, and all parts are thoroughly washed, for example, with carburetor cleaner in an aerosol can. A clean throttle will ensure high-quality and uniform engine operation at idle.

When replacing the regulator, you must remove the terminal from the battery . This is not only a safety issue during any work on the engine, but also to ensure normal calibration of the initial position of the IAC rod. Typically, sensors are sold in a cocked state, when the rod is recessed as much as possible. This can be checked by measuring the distance from its cap to the mating flange. It should not be more than 23 mm, otherwise the valve will be pressed into the seat after tightening the fastening screws and damaged.

By connecting the connector to the sensor and replacing the terminal, you can turn on the ignition . The engine control processor will immediately work out the initial position of the rod and ensure normal starting of the motor.

Smooth and stable operation of the engine at idle speed, controlled by a stepper regulator, is very important both for engine life and for traffic safety. A suddenly stalled engine can cause big trouble. Therefore, you should never delay repairs, that is, replacing this simple and inexpensive device.

Even if you manage to avoid undesirable situations on the road, subsequent breakdown and unscheduled engine repairs will cost much more than 500 rubles , which, to a first approximation, a good IAC can cost. The price, of course, is inaccurate, since the production of this device, the original number of which begins with the numbers 21203-1148300, has been mastered by many enterprises.

Causes of malfunction and methods of elimination

When troubleshooting, it is not always necessary to replace the idle speed sensor; there may be other reasons that cause failure of the actuator unit.

Oxidized contacts, a broken connector, or a worn wire interrupt the flow of voltage to the actuator. Before disassembling the sensor, the quality of connections of all electrical cables is checked, the battery terminals and connector are cleaned.

In 40% of cases when element failure was diagnosed, the reason was the presence of dirt, dust, or oil particles that clog the movable element of the regulator and stop it. It is necessary to replace the air filter on time and keep the throttle body clean.

Electric motor burnout. This malfunction refers to a direct failure of the sensor, which has a rod and an electric motor in the circuit. You can find the fault by disassembling the sensor into parts and checking it with a multimeter.

Checking with a multimeter

Since the sensor is mechanical and in principle a conventional DC motor in design, the test is carried out by measuring the resistance of the IAC winding.

To test with a multimeter, set the switch to measure 200 ohms.

We connect the multimeter probes to the central terminals of the IAC and measure the resistance on them. The meter reading on the screen should be close to 50 ohms. If the device displays 1 or infinity, the winding is most likely broken.

If the winding breaks, the idle speed regulator VAZ 2121-2123 must be replaced with a new one.

Accelerator sensor

In addition, the Niva Chevrolet throttle sensor can affect the smooth operation of the engine at idle. This component controls the amount of air mixture entering the cylinders. The main task of this part is to make this quantity optimal for high-quality ignition.

The Chevrolet Niva throttle valve is regulated by a special sensor, which, if necessary, closes it, creating a vacuum in the intake system, or opens it, letting in the air mixture.

If the TPS is faulty, faults are displayed during the period of inactivity. In this case, you need to remove the element and carry out diagnostics.

Description of IAC

This sensor is quite unreliable, often subject to breakdown and replacement. Due to its unreliability, it was subsequently abandoned in favor of an electronic throttle.