When you press the gas on the VAZ 2109, the carburetor stalls - reasons

VAZ engine

Sometimes such a nuisance happens on the way, the driver finds himself in a situation where the engine of a VAZ 2109 stalls in the middle of the road and it is impossible to start the car further. The most interesting thing in such a situation is that there were no traces of any signs warning (foreshadowing) these problems, the car drove as usual, there was no “sneezing” or “shooting in the muffler.” Since the problem is common, our instructions will tell you what to do in a situation such as a sudden stop of the engine and poor starting. We will consider in detail all the main reasons that cause the engine to stop at idle and while driving. And also the reasons why it does not start when warm and how to solve this kind of problem.

The engine choke when you press the gas VAZ 2109 carburetor

A fairly common situation during the operation of a vehicle is when failures occur when pressing the gas pedal, the engine stalls when over-accelerating, the power unit does not pick up speed, choke, etc.

Let's start with the fact that there can be many possible reasons for this type of malfunction. In the process of initial diagnosis, an important condition is the observation of characteristic symptoms, which allows you to more accurately and quickly determine the malfunction. Next, we will look at why the engine stalls when you press the gas pedal, as well as in what cases the engine stalls when you press the gas.

Why might the carburetor stall after warming up?

To understand the cause of this problem, it is best to contact motorists who have already encountered such a problem. Whatever happens to your car, remember that similar problems have most likely happened to other car owners. Therefore, you should visit specialized forums or simply chat with other motorists. In this case, you can find several options for answering your question. After warming up, the carburetor completely closes the choke valve, leaving the accelerator valve in working condition. If the idle speed is set incorrectly, the engine will only run on choke. But this is the basic reason; there are several other popular problems:

• rapid engine overheating and serious problems with the cooling system of your power unit;
• very poorly adjusted valves - adjustment has not been made for several years in a row;
• the carburetor is not adjusted, the mixture is too lean, the system blows too much air into the combustion chamber;
• the mixture can also be overly rich, which causes fuel overflow and problems in some carburetors;
• the carburetor jets are clogged, fuel flows poorly through them, which causes problems in the quality of the mixture;
• gasoline is incredibly bad, the filters are clogged, the flow rate of the fuel system has become much lower;
• Certain problems have arisen inside the carburetor, membranes and gaskets have broken, and fuel is leaking.

The latter case is especially popular on domestic cars. Due to improper operation of the fuel pump and other troubles, which may well become a problem in the functioning of the power unit, the carburetor simply stops working normally, its main functions are disrupted due to damage to internal parts. This is also one of the most difficult types of breakdowns, so you will have to invest a lot of time or money to solve this problem. Therefore, first you should check and eliminate other possible problems that could cause such troubles. In particular, you can check all the previous points, which could also cause the carburetor to perform poorly and stop functioning when hot.

The engine stalls when you press the gas: possible reasons

As already mentioned, certain signs allow you to localize the existing problem. For example, if the engine stalls when “cold” after pressing the gas pedal only when the humidity outside is high, moisture may well be the cause.

1. The problem is that water particles can accumulate on the distributor cap. Such accumulations of moisture settle on the inner surface of the lid in the form of condensation. Let us add that on some cars the cover is shaped in such a way that allows current to pass through the distributor, that is, the discharge is simply not supplied to the spark plugs. At the same time, at idle, the internal combustion engine operates normally, but when you press the gas, the problem manifests itself. This is explained by the fact that the distributor, at the moment of gas supply, begins to operate in an accelerated mode, passing a larger amount of electricity. Taking into account the fact that moisture has accumulated in the distributor housing, a malfunction immediately occurs and the engine choke, as a weak spark is formed at the spark plugs. To check, it is enough to observe whether such a failure is present on a warm engine, and also whether the malfunction appears when it is dry outside. You can also put the car in a heated garage or parking lot for several hours, and then evaluate the stability of the internal combustion engine after starting and at the moment you press the gas.
2. Another reason why the unit may choke is that there is no vacuum in the fuel system. In other words, air leakage occurs, which affects the fuel pressure and the composition of the fuel-air mixture. Usually the problem progresses gradually and can occur on both a cold and hot engine. The fact is that in order to accurately determine the amount of fuel supplied at a specific point in time, the vacuum in the fuel system plays an important role.

How to help the engine work

Sometimes the VAZ 21099 carburetor does not start well. To help a cold engine work, you need to perform the following steps.

1. Press the handle of the fuel pump to pump gasoline into the carburetor float chamber.
2. Place the gearshift lever in neutral position.
3. Pull the choke toward you, closing the throttle valve, and with the ignition on, try to crank the starter. If unsuccessful, repeat the action after some time.
4. If the car starts, let it idle, release the throttle and take your foot off the clutch pedal.
5. In the cold season, try to turn the crankshaft several times, turn the headlights on and off, pull out the choke handle, squeeze the clutch and turn the starter. In winter, to keep warm and improve engine performance, it is recommended to wrap the radiator grille. When the engine starts, the pressure control and battery charging lights on the operating panel should go out.

The driver starts the car

When the car is warmed up, its engine should start running immediately. Other situations arise when the machine does not. Starting a hot engine should take place with the throttle valve open and the gas pedal depressed to one third of its full travel. As soon as the engine starts, you need to release the accelerator pedal. If the start is unsuccessful, repeating the described steps may lead to difficulty starting the engine and flooding the spark plugs with gasoline. If this does happen, the turned out candles must be dried with air.

Carburetor or injector

While the whole world has made a choice in favor of injection engines, in our country the intensity of the debate on the topic “injector or carburetor” does not subside. Mostly, the debate revolves around the possibility of field repair of an engine with a carburetor or an injector. Adherents of the first passionately prove that a failed carburetor engine can be easily repaired literally “in the open field.” And if the injection engine fails, prepare a tow rope and go to the service center.

Proponents of injectors raise the objection that injection engines break down much less often, and there are only two typical malfunctions.

1. Damage to the crankshaft position sensor.
2. Fuel pump failure.

At the same time, the “injection guys” rather sarcastically clarify that the fuel pump can just as easily break down on a carburetor engine, and the sensor costs a penny and can be easily changed even in the field. Perhaps we should admit that the supporters of injection are somewhat right. But if you happen to drive a carburetor version, then you shouldn’t chase the illusory savings of a glass of gasoline per 100 kilometers. You shouldn’t start switching to a new type of power system just because the VAZ 2109 carburetor failed when you pressed the gas pedal.

If something happens, the carburetor “nine”, even if it sneezes in blue puffs, even with a sinking accelerator pedal, will take you home - after all, it’s worth something.

Fuel line

Stable operation of the carburetor in idle mode is controlled by a jet. If the nozzle malfunctions, it must be unscrewed and purged with air under pressure, thereby removing dirt particles. In case of serious blockage, you can resort to flushing with a diluted mixture of gasoline or acetone.

On some VAZ 2109 models, jets with a valve are installed

, which has electromagnetic control.
This valve regulates the flow of fuel into the nozzle. During normal operation, the fuel supply stops when the engine speed exceeds 2100 rpm. The valve opens again when the speed drops to 1900 rpm
.

It is possible to diagnose its breakdown only with the use of special equipment at a service station. However, there is also a “folk” method of verification. To do this, it is enough to quickly disconnect and connect the power supply wire to the valve while the engine is running.

At the moment of such manipulation with the wire in the valve, you can hear a click, which will indicate its working condition.

Fine filter

fuel mixture is installed on the fuel line in front of the pump to supply gasoline to the carburetor. According to the regulations, it must be replaced with “2109” every 15,000 km, but this is subject to high-quality fuel. Uneven operation of the engine (jerky) at idle and high speeds may indicate that it is clogged.

In this case, it must be replaced; purging will probably only be effective if you need to go to a car dealership to buy a new filter.

Ozone or Solex

With the start of production of the VAZ 2108 and 2109, AvtoVAZ designers abandoned the use of Ozone carburetors, in which many complex options had no practical meaning. What was the cost of the forced idle economizer alone, which supposedly served to save fuel during engine braking? Neither engine braking became widespread, nor did the EPKH bring any noticeable savings, but it provided drivers with quite a few headaches when pressing the gas.

When switching to “eights” and “nines”, the plant returned to a simpler version of the carburetor. It was distributed under the name Solex: after the name of the French company that produced its prototype. Solex lost the pneumatic drive for the secondary chamber damper, a semi-automatic starting device, and an autonomous idle system.

The design has been simplified and reliability has increased. It is Solex that, as a rule, owners of carburetor versions of the VAZ 2109 deal with.

Removing the device

If you nevertheless determine that the idle speed sensor is broken, then you will need to replace it with a new one. To dismantle this part, no special skills are required. The above-mentioned VAZ 2109 and 21099 sensor is installed on the throttle body body and attached to it with two bolts, for example, like a fuel pump. In order to remove this device, it is enough to unscrew the two mounting bolts and remove the bundle of wires connected to the device. Before performing this work, it is recommended to disconnect the battery by removing both terminals from it.

Non-carburetor causes of engine failure

Car owners usually refer to failures as unpredictable short-term interruptions in the operation of a car’s internal combustion engine. Failures belong to the category of so-called “unreasonable”, or, more precisely, multi-cause failures. It is impossible to say unequivocally about such breakdowns: failures appear - change the spark plugs. More precisely, it is possible to say, but it is not a fact that after replacement the failures will disappear. Although this also happens.

So failures in the operation of a carburetor engine are not necessarily related to the device itself. And before you start working on such a complex unit, you should exclude the influence of other reasons.

1. Mechanical failure of the drive.
2. Ignition system malfunctions.
3. Failures of the power system located outside the carburetor.

These groups of negative factors stand out among others. Let's look at them in detail.

Remove the outlet pipe from the fitting. Press the fuel pump manual drive lever vigorously. There should be an intense stream of fuel coming out of the hose. If not, the pump is faulty and must be repaired or replaced. Clean the fuel line filters from the tank to the carburetor, and blow out the pipelines themselves.

If everything is in order with the power and ignition systems, move on to the carburetor itself.

VAZ injection engines

In injection engines VAZ-2110, 2112, 2114, 2115, both 8-valve and with a timing belt with 16 valves, it is more difficult to identify the cause of the decrease in power due to the more complex design of the main systems.

Supply system

Any injector consists of a mechanical executive part and an electronic control part, and problems can arise in both of them, which will lead to a drop in power.

Let's look at the mechanical part first. Here, cravings can be influenced by:

• Severely clogged mesh filter on the fuel pump;
• Decrease in fuel pump performance due to wear;
• The fine filter is dirty;
• Malfunction of the fuel rail pressure regulator;
• Clogged injectors;
• Fuel filter dirty;
• Air leak in the manifold.

In general, almost every element of the injector executive part can be the culprit for a decrease in dynamics.

The situation is approximately the same in the electronic component.

The operation of the engine with the injector is controlled by an electronic unit, which constantly monitors the parameters through sensors installed on different systems.

The number of these tracking elements is considerable and the breakdown of any of them leads to the fact that the ECU incorrectly evaluates the indicators on the basis of which it controls the executive part.

Thus, the lambda probe, DPKV, mass air flow sensor, DPZ, phase sensors, detonation sensors and coolant temperature sensors in the event of a breakdown lead to a decrease in power, so you will have to check all of them in search of the cause.

Ignition and exhaust system

As for the ignition system of injection engines VAZ-2110, 2112 and others, the reasons may be:

• Candles;
• High voltage wires;
• Ignition module.

Another possible cause could be a misalignment of the generator drive pulley (with the ring gear).

IMPORTANT TO KNOW: What is an adsorber in a car. Because of this, the DPKV readings are disrupted, as a result the operation of the ignition system is disrupted, which leads to a drop in traction

Because of this, the DPKV readings are disrupted, as a result the operation of the ignition system is disrupted, which leads to a drop in traction.

In injection engines, the exhaust gas removal system more often creates this problem than in a carburetor car, and all due to the use of a catalyst.

The element's honeycombs have a small cross-section, so they become clogged quite quickly, which leads to exhaust gases “crushing” the engine.

Also, if the engine does not pull, check the lambda probe.

Air leak

Problems with engine operation often occur due to air leaks in the fuel system.

Where can there be air leaks on a VAZ 2109

Potential air intake locations:

1. Due to the deformation of the metal from which the parts are made, suction occurs between the carburetor body and its top cover.
2. The spaces between the lower platforms of the carburetor units and the intake manifold.
3. Unreliable connection of the hose to the fittings of the vacuum brake booster.
4. Vacuum booster malfunction.

The operation of the latter is checked simply: the vacuum hose is disconnected from the intake manifold, the fitting is plugged and the engine is started.

If the engine stops running after placing the plug back on the fitting, then the problem was in the amplifier.

What to do if cars with automatic transmission stall?

If your vehicle has an automatic transmission, then the problem should be found in the electrical supply. If you abruptly switch from one gear to another, or while switching gears while braking, the settings may be distorted, and the on-board computer will receive a signal to turn off the engine.

Also, models with automatic transmission may stall due to malfunctions of the hydrodynamic transformers of the gearbox. This problem mainly manifests itself during acceleration and requires urgent intervention from car service specialists.

Accelerator pump failure

What causes problems with the accelerator pump:

• Incorrect spray dosage or channel blocked by debris.
• Worn (torn) diaphragm.
• The pump drive is incorrectly selected.

Factory-made sprayers have two strokes directed into the chambers. Most experts are sure that the second “spout” in this system is superfluous, so you can install a sprayer with one stroke, as, for example, on the Niva.

You need to check the presence of the atomization process by removing the carburetor and unscrewing the top cover. In this case, fuel must be filled into the float chamber. The throttle valve opens, and two jets pass through the lower part of the housing without touching it - this is a sign of serviceability.