Why does the engine Niva: causes and solution

The situation when niva troitThis is a condition in which the engine is unstable, loses power and emits a characteristic "twitching" exhaust sound, can be taken by surprise on the track or in the back taiga, and most often the problem lies in the failure of the ignition of the fuel-air mixture in one of the cylinders, which disrupts the balance of the entire power unit.

You can't ignore this symptom. VAZ-2121 or more modern modifications Niva Legend and Niva Travel They're operated with a idle cylinder, which causes the catalytic converter to collapse rapidly, overheat the engine, and run high fuel consumption, and in some cases, unburned gasoline gets into the oil, liquefying it and causing oil starvation of the rubbing vapors.

In this article, we will discuss the main reasons why troiteAnd we'll come up with a clear algorithm for finding a malfunction, and you'll learn how to tell the difference between an ignition problem and a mechanical motor failure, and what tools you'll need to make an accurate diagnosis in the field or in the garage.

Primary Diagnostics: How to Determine a Problem Cylinder

Before you grab the tools, you need to localize the search area. Niva Chevrolet Or the classic Niva Troit at idle speed, the first thing you should do is listen to the sound of the engine. A idle cylinder often gives off its characteristic "cove", and the exhaust pipe makes an intermittent sound, resembling shots.

The easiest and most reliable way to find the culprit is to turn off the culprits in a series of turns, and if you turn off the ignition coil connectors (or high-voltage wires on the carburetor versions), if you turn off one of the cylinders, the nature of the engine does not change, and the tripling increases or remains the same, then you have found a non-functioning element.

However, be careful: on injection models with an electronic control unit (ECU) Prolonged shutdown of cylinders on the working engine can lead to an error of the oxygen sensorDo this quickly, literally for 1-2 seconds, so that the ECU detects a change in operation, but does not go into emergency mode or damage the catalyst with unburned fuel.

You should also pay attention to the color of the candles after checking, and by twisting the candles, you can visually assess the condition of the cylinder: a black, smoked candle indicates a rich mixture or spark problems, and a whitish plaque indicates overheating or poor mixture, which will help narrow the search to a specific system.

Failures of the ignition system: candles, coils and wires

The most common reason why VAZ-21214 or VAZ-21213 The ignition plugs are consumables, and their condition directly affects the stability of the engine, the enlarged gap between the electrodes or the breakdown of the insulator does not allow you to create a powerful spark sufficient to light the mixture.

In injection Nivas equipped with individual ignition coils, problems can be associated with the breakdown of the coil itself or oxidation of contacts in the connector. High humidity, water entering candle wells when washing the engine or driving through puddles often lead to the fact that the current goes “by the mass”, without reaching the candle.

• 🔌 Checking of high-voltage wires: On carburetor models inspect the wires for cracks and breaks (especially noticeable in the dark).
• 🕯️ Condition of the candles: The gap must meet the specification (usually 0.7-0.9 mm), the electrodes must not be melted.
• 🔋 Ignition module: Check the reliability of the attachment and the absence of oxides on the contacts of the module.

If the problem persists after replacing the candles and checking the wires, the ignition module or the coil itself may have malfunctioned. On older models, the module could have failed due to overheating, since it is located in close proximity to the hot engine.

So if you've replaced the whole set and the engine is still working, try moving the candles in places, and if the three runs over to the other cylinder with the candle, it's the defect in the candle.

Problems with the fuel system and nozzles

If the spark is all right, the next suspect is the fuel system. Niva's trembling on cold Or hot, the cause may be clogging or malfunctioning fuel injector. The nozzle may "pour" fuel without closing tightly, or, conversely, be clogged with sediments and not supply enough gasoline.

You can hear the nozzles by putting a stethoscope or just a long screwdriver on the nozzle body and pressing your ear to the handle. You should hear clear, rhythmic clicks of the valve opening. If there are no clicks or they are deaf, the nozzle needs cleaning or replacement. It is also worth checking the electrical connector: often oxidized contacts or rubbed wires in the tourniquet.

Another important aspect is the pressure in the fuel ramp: If the fuel pump dies or the fuel filter is clogged, the pressure may not be enough for all cylinders to function normally, although more often this manifests as a total loss of power rather than tripling. However, if one injector receives less fuel due to air traffic or pollution, the cylinder will stop working.

⚠️ Attention: Before removing the fuel ramp, be sure to relieve pressure in the system. To do this, remove the fuel pump fuse on the cold engine and let the engine work until it decelerates, or press the pressure relief valve in the ramp, substituting a cloth.

Poor gasoline is a scourge of domestic roads, and water in a tank or a lot of impurities can quickly disable the nozzle sprayer. If you fill up at a suspicious gas station and the car starts to triple, first of all drain some of the fuel through the filter and check it for water.

Mechanical causes: compression and GRM

The worst case scenario is when the three-ways are caused by mechanical damage inside the engine. VAZ-2121 Troit and at the same time heard metal knock or hiss, perhaps burned valve or gasket GBC. In this case, no replacement candles and wires will not help.

The first step in diagnostics is compression measurement, which requires a compressometer, which is measured on a warm engine with a fully open throttle and twisted candles, the normal compression for a Niva engine is 10-12 atmospheres, the range of values between the cylinders should not exceed 1 atm.

Indicator.	Norma.	Critical significance	Possible cause
Compression	10-12 atm	Less than 8 atm.	Wear of piston rings
Pressure scattering	Up to 1 atm.	More than 2 atms	Flare or gasket
Oil pressure	0.8-1.0 bar (on singles)	Less than 0.6 bar	Wear of the oil pump or liners

If the compression is low, you can do an oil test. Put 5 to 10 ml of engine oil in a low compression cylinder and repeat the measurement. If the compression is increased, the piston rings are a problem (the oil has sealed the gap); if it remains low, the valves or the gasket are a problem.

If a belt or a GRM chain jumps on a tooth, the valves will open and close in a wrong time, which will lead to unstable operation and trigion. On the chain-driven Nivas (VAZ-21213, 21214), chain stretching is a frequent phenomenon, especially at large runs.

How to distinguish a breakdown of the gasket of the GBC from a burn valve?

When the gasket is broken, there is often a withdrawal of antifreeze, a white emulsion on the oil probe and bubbles in the expansion tank. The valve burn is usually accompanied by a loss of compression in one cylinder without external symptoms of fluid leakage, although the characteristic cotton can be heard in the intake or exhaust.

The influence of sensors and electronic control unit

Modern injection Nivas are packed with electronics, and malfunctions can mimic mechanical malfunctions. If the engine is troubling, but the ignition system and mechanics are fine, you should pay attention to the sensors, in particular, the crankshaft position sensor (CRP) and the throttle position sensor (TRP).

Incorrect readings of DPCV can cause the ECU to give a spark at the wrong moment when the piston is at the top dead point. This causes hard work of the engine and tripling. Check the gap between the sensor and the flywheel crown - it should be about 1 mm. The presence of metal shavings on the end of the sensor can also distort the signal.

• 📉 Mass air flow sensor (MADR): When it fails, the mixture may be too poor or rich, causing ignition misses.
• 🔌 Lambda probe: If the oxygen sensor is lying, the ECU will correct the mixture incorrectly, leading to instability.
• 💻 EBU errors: Reading error codes through the OBD-II diagnostic connector often points to a specific cylinder or system right away.

To accurately diagnose electronics, you need a scanner. You can connect to the connector and see the ignition gaps in real time (Misfire count setting), which is the fastest way to know which cylinder is floundering without knowing the coffee grounds.

⚠️ Attention: Do not turn off the sensor connectors on the engine running. This can lead to a voltage surge and damage to the ECU. All manipulations with electricity are carried out with the ignition turned off.

Specificity of work on gas (HBO)

Many owners of the Niva install gas cylinder equipment (GBO) to save money. Niva's on gasBut it works smoothly on gasoline, and the problem is almost certainly with the settings or the health of the gas equipment, and the gas requires a more powerful spark and has a different octane number, so the ignition system requirements are higher.

The gas burns at a higher temperature, and if you don't warm up the engine before switching to HBO or drive at high speeds, the valves can burn out, and it's also worth checking the evaporator gearbox: if it freezes or water from the cooling system gets into it, the gas supply will be disrupted.

Try switching to gasoline. If the threes are gone, adjust the gas injectors, check the HBO filters and the condition of the candles (for gas, special candles with a reduced gap are recommended). If the car is troying on both gasoline and gas, look for the reason in the mechanics or gasoline system.

Frequent Questions and Answers (FAQ)

Why does Niva only triple on a cold engine?

This may be due to improper operation of the idling regulator (RXX), sucking unaccounted air through cracks in the intake manifold or a malfunction of the temperature sensor that gives incorrect data to enrich the mixture.

Can I drive if the engine is running?

Long driving with a idle cylinder will lead to overheating of the catalyst (up to its melting), liquefying of oil with gasoline and increased wear of the engine. You can get to the service, but carefully and at low speeds.

Which candles are better to put on the Niva?

The best choice is candles with a potassium number of 17 (GOST) or 6 (NGK / Denso). NGK BPR6ES, Denso W20EPR-U or domestic AU17DVRM. For GBO, it is better to take iridium candles.

Why did Niva start to triple more after replacing candles?

Maybe the new candles have an inappropriate potassium number, too much gap, or the thread/insulator was damaged during installation, and also check if the candles are tightly twisted and the wires are connected before clicking.

How often should I change candles on the Niva River?

The recommended interval of replacement is every 20-30,000 km for ordinary nickel candles. Iridium candles last longer, up to 60,000 km, but their condition should still be checked at each maintenance.