In this article we will take a closer look at the situation when a carburetor engine of a passenger car (VAZ 2108, 2109, 21099, 2105, 2107 and their modifications) starts and stalls due to a carburetor malfunction. Malfunctions of carburetors 2105, 2107 Ozone, 2108, 21081, 21083 Solexi and their modifications will be considered.
Symptoms of a problem
— The engine starts, runs for a few seconds and stalls, repeated starts are unsuccessful.
— The engine starts with difficulty, after running for a short time it stalls, after restarting it starts and runs.
— The engine starts and immediately stalls, starts again and stalls again, and so on several times, but then it still starts working.
Causes of malfunction
There is no fuel in the float chamber
Pump it up using the manual pump lever on the fuel pump.
Trigger diaphragm damaged or out of adjustment
Disassemble the starter housing and replace the diaphragm with a new one. Adjust the starting device.
carburetor starting devices 2108, 21081. 21083 Solex, 2105, 2107 Ozone Fuel and air jets, emulsion wells and tubes of the main dosing system are clogged
It is necessary to remove the carburetor cover, unscrew the jets, remove the tubes, rinse and clean them, clean the wells, blow everything with compressed air and put it back. The image shows what needs to be cleaned on the carburetor 2105, 2107 Ozone.
On the Solex carburetor, we unscrew the air jets and take them out along with the emulsion tubes. At the bottom of the opened wells there are fuel jets. We turn them out with a thin long slotted screwdriver. Clean, rinse with acetone and blow with compressed air.
fuel and air jets, emulsion tubes and emulsion wells of GDS carburetors 2108, 21081, 21083 Solex, 2105, 2107 Ozone Fuel and air jets and idle system channels are clogged
Unscrew the jets, rinse and clean them, and blow them with compressed air.
air and fuel jets for CXX carburetors 2108 Solex and 2105, 2107 Ozone The fuel level in the carburetor float chamber is broken
The fuel mixture is either very lean or very rich due to incorrect adjustment.
approximate fuel level in the float chambers of carburetors 2108, 21081, 21083 Solex, 2105, 2107 Ozone Articles on the site about adjusting the fuel level:
The carburetor air damper drive is not adjusted (“choke”)
What to do if the VAZ injector starts and stalls at idle? This problem most of all concerns old cars, since with age various contaminants accumulate in the fuel system and in the vehicle, as well as sensors and mechanisms wear out - all this will inevitably lead to changes in engine operation.
We will describe in order all the reasons that lead to this problem.
- The first thing to check is the mass air flow sensor (MAF). The sensor's sensing element becomes dirty and wears out with age, which is why its resting voltage increases and its reaction time to changes in air flow increases. If the quiescent voltage exceeds 1.035V, you should think about replacing the sensor, because it will no longer be able to give inflated readings on air flow. The electronic control unit will supply more fuel and the mixture will be over-rich - and this will have a very bad effect on all engine operating modes, as well as on idle stability.
- The idle air control (IAC) can also affect the stability of the engine. Rod jamming is the most typical malfunction in it. In addition, with age, natural wear and tear occurs on the components of the regulator, and this leads to problems with movement. The usual service life is 100-150 thousand km. Only with the help of special equipment can you check the IAC, and it is better to replace it with a new one immediately if a malfunction is suspected.
- Very often it is enough to simply clean the throttle assembly from dirt. It's easy to do it yourself. These are the most basic cases that you need to pay attention to. Atypical situations will follow.
- Sometimes the problem is a leaking intake manifold. You need to check the gaskets, vacuum hoses, injector O-rings, and the vacuum brake booster and manifold plugs. The easiest way to find air leaks is with a smoke generator.
- Pay attention to fuel pressure.
- You also need to check the ignition system and spark plugs in particular.
In conclusion, it should be noted that without special equipment, a complete check of the system is impossible. Only with its help can the fault be accurately identified.
Owners of VAZ 2107, 2110, 2112, 2114, and other cars, may encounter a problem - the car starts and immediately stalls. The engine starts, but after a few seconds the speed drops and the engine stalls. Let's look at possible causes of startup failure and ways to eliminate them.
First, you need to go through the most obvious options.
- Gasoline (diesel fuel) has run out. No matter how paradoxical it may sound, drivers often forget to monitor the level of fuel in the tank.
- On diesel engines (especially in winter), the reason that the car starts and stalls almost immediately can be frozen fuel.
- The quality of gasoline at gas stations is often appalling, so if you fill your car with low-quality fuel, you may encounter the problem of a stalled engine. If there is only a little bad gasoline, you can dilute it with good gasoline. But if the tank is full, then it’s better to drain the surrogate out of harm’s way.
- Worn wires and old (faulty) spark plugs are also quite often the cause.
- Engine compression, or rather its absence, can provoke a situation in which the engine stalls barely having time to “catch up”. But this is already a very serious breakdown, the appearance of which is accompanied by a host of other symptoms, which are simply impossible not to notice during the operation of the car.
The injector starts and stalls
Fuel-injected cars may behave this way due to a faulty fuel pump. It's in the tank. It is very easy to check its functionality. If you turn the ignition key to the first position and listen, you will hear the pump working, pumping gasoline into the system. 
Severe contamination of the fine fuel filter can also cause the car to stall after starting. The filter simply does not have time to pass the required amount of gasoline.
ECU errors quite often lead to problems with starting the engine, not receiving signals from certain sensors, or receiving them in a distorted form. It is best to diagnose such breakdowns in specialized services.
Why do carburetor cars start and stall?
If the car starts and immediately stalls, the problem may be due to a lack of fuel in the float chamber. You can try manually pumping up the fuel pump. It must be checked for functionality and, if necessary, replaced.
Before you independently clean the power system in general and the carburetor in particular, you should remember that any unconscious manipulations can lead to a large increase in fuel consumption.
Another reason why the engine stalls is that the mesh filter in the carburetor in front of its inlet is clogged. If the car starts and stalls after a few seconds because of this filter, then it needs to be cleaned and washed. To do this, use a toothbrush and a solvent (gasoline or acetone). After this, immediately, together with the filter, clean the slot into which it is inserted. 
It happens that in VAZ cars, a few seconds after starting, the speed drops due to a malfunction of the solenoid valve. The test is carried out as follows: the valve is unscrewed, power is supplied to the positive contact, and the housing is shorted to engine ground. If the valve is working properly, a distinct sound will be heard and the needle will enter the body. 
You can simply connect a wire to the valve and put it in place. If you do not hear a click, the valve is faulty. We unscrew the valve and remove the jet from it. If it is bent, it needs to be replaced. Make sure that the valve shut-off needle moves freely, that the valve gasket is not torn and that it is sealed tightly against the body.
If the valve clicks, then you need to diagnose the EPH system. The idle fuel jet may need cleaning. If the car engine speed drops, its clogging can affect the stability of operation. To clean the nozzle, it is necessary to create increased vacuum in the system channels.
To do this, start the car and raise the speed to 3000. Turn out the jet holder (solenoid valve) a few turns. This allows you to create the required vacuum in the channels. We repeat the procedure several times.
Other reasons for incorrect starting of the VAZ 2107 engine
Another common problem that causes the engine of VAZ 2107 cars to start and stall is excess air getting into the carburetor. In this case, the fuel mixture cannot keep the engine running for a long time, and although the car starts, it stalls after a few seconds. It is necessary to determine the location of the air leak and eliminate the gap.
It happens that the jets and pipes of the dosing system become clogged. This also affects the drop in engine speed, so that the VAZ 2107 stalls after a few seconds. What to do in this case? You need to unscrew the jets and pipes under the carburetor cover and clean them. After this, blow out the wells and jets with compressed air. If you have a Solex carburetor, then you also need to clean and blow out the fuel jets located at the bottom of the wells.
Adjusting the fuel level in the float chamber (Solex carburetors)
In addition to all of the above, engine speed drops if the fuel level in the carburetor (float chamber) is incorrectly adjusted. As a result, there is either not enough gasoline in the fuel mixture or too much of it.
When adjusting the VAZ 2107 carburetor, it does not need to be disconnected from the engine. Follow these steps:
- remove the air filter housing by unscrewing all the fasteners;
- remove the carburetor cover;
- check the position of the floats. To do this, separate and bring them together to achieve the correct location.
It is necessary to achieve such a position of the floats so that they move freely without clinging to the walls of the chamber in which they are located. It will not be superfluous to measure the distance from the protrusions on the floats to the paper gasket. The distance should be within 0.75–1.25 mm. Use a feeler gauge to measure. 
What to do if it is far from normal? In this case, you need to adjust the height of each of the floats.
As we have seen, there are many reasons why the engine stalls. To start the engine correctly, you need to check and eliminate all the above faults. Afterwards, if the problem is not resolved, you will have to contact specialists.
Situations when a VAZ injector starts up immediately and then immediately stalls arise quite often. And all because of the fuel injection system (forced type). To correct this situation, car owners often use a heating plug, but this is not a solution to the problem, but only a temporary measure. If a VAZ 2107 starts and stalls immediately after turning the key in the ignition, then in most cases this indicates a problem in fuel delivery (the fuel pump is clogged or not working correctly), or the quality of the fuel used leaves much to be desired, and the injectors are simply clogged. And the car starts only on the remaining fuel in the cylinders.
Finding the faulty component
So, what should you do if the engine starts easily, but then immediately slows down and stalls? The first thing you need to do is check for carbon deposits on the spark plugs. If some of them are covered with a layer of carbon deposits, then the engine a priori cannot operate normally. It first starts due to the movement of the starter, but immediately after that it brakes, since several cylinders are physically unable to withstand the entire load from the crankshaft. The carburetor, by the way, can also fail due to such a problem.
So what is the cause of engine failure? If the car starts, then at least the spark is fine. That is, the electrics work as expected. It wouldn’t hurt to unscrew the heads and try to find those spark plugs that are covered with a layer of soot. You can clean them by burning them over a gas burner and cleaning them with alcohol (this can only be done when the contacts are cold).
The injector itself may also become clogged. In this case, the fuel supply to the combustion chamber simply does not work. The following actions should be taken:
- remove the blocks and check the valves;
- check the operation of the sensors;
- check whether the engine operates normally at temperatures above 80ºС.
Naturally, the fuel pump itself can also fail. When the engine starts, the injector turns automatically due to the starter, and then the thrust comes from the generator. If one of these components is not working correctly, the car will simply stall. Here again we are talking about the residual amount of fuel in the cylinders. If the engine immediately stalls, and along with it the starter also works unevenly, then most likely the problem is either in it or in the ignition switch.
You should try to replace it with a known good one and retest the engine operation. As a last resort, the contacts are simply clamped.
What to do if the problem is in the ECU?
The engine may not operate properly if the on-board computer malfunctions. At VAZ, it is he who is responsible for the timely supply of fuel, synchronizing the operation of the injector nozzle and spark plugs. When the engine stalls immediately, this indicates a mismatch in the timing of fuel supply and ignition of the fuel mixture.
As a rule, changing the firmware or restoring it to the factory state helps. Although sometimes it may simply be necessary to adjust the fuel supply cycle, as well as the saturation of the mixture. In extreme cases, on a VAZ 2110 (or later model), you will have to replace the entire ECU unit or turn it off, switching the engine to manual operation only.
It should be noted that not only the ECU itself is responsible for the operation of the engine, but also a bunch of sensors that regulate the pressure in the injector, the saturation of the mixture, and the ignition timing.
That is, you need to check their work. Although, if a malfunction is detected in one of them, a Check Engine signal should be sent to the dashboard. This, for example, happens when the VAZ 2110 starts up. This does not happen only if the ECU simply does not receive signals from the sensors. It is worth noting that the model 2107 does not have a computer installed by default, but the injector does not work without it.
Similar problems arise when the carburetor is synthetically converted to an injector, but the same on-board computer is retained. They simply change the firmware in it, connect new modules, but you need to understand that it was not originally designed for such work. Thus, if the carburetor is rebuilt, then the ECU must be changed along with it to a compatible model. Fortunately, VAZ took care of their release.
So, if the injector starts up and immediately stalls, then the main reasons for such a malfunction are malfunctions in the electronics (including the ECU), improper operation of the fuel system, or problems with gasoline filtration. Identifying the root cause is not a problem. As a last resort, you can always contact the service center. But it is worth remembering that any adjustments to the operation of the on-board computer can only be made if the engine is in full working order.
Here we will analyze in detail all the possible reasons why the carburetor stalls in a VAZ 2107. In most cases, the breakdown can be repaired yourself, but sometimes a complete replacement of the carburetor will be required.
If you notice some of these phenomena in the operation of the VAZ 2107, then you should carefully check the carburetor. You may find something broken in it.
- If the VAZ 2107 starts and immediately stalls, the carburetor may be the cause. All subsequent attempts to start the engine will be unsuccessful.
- In cases where the engine is difficult to start, the carburetor should also be checked. The car may stall after a short time of operation.
- If the engine stalls immediately after starting, this is also a sign of a carburetor problem. The engine will stall several times, and only after numerous attempts will you be able to start the VAZ 2017.
Causes of failure of the carburetor VAZ 2107
Here we will describe step by step all the possible reasons that the VAZ 2107 starts and stalls.
If the cause of a carburetor breakdown is the lack of fuel in the float chamber, then there is a high probability that the fuel pump or power system is also faulty. Simply remove the hose from the fuel inlet fitting. After this, make a couple of presses on the lever to manually supply fuel. Gasoline should flow out of the hose hole. If the stream was weak or completely absent, then you need to carry out a detailed check of the fuel pump and power system.
A clogged filter is also a common cause of carburetor failure. It will be very easy to correct this reason. You will need to remove the strainer and then clean it. For cleaning purposes, you should use a toothbrush, or something similar.
You can try rinsing the filter with acetone. A can of compressed air can also help. Blow through the entire filter with it. Clean the filter seat. Sometimes it may be necessary to completely replace this part, but it is better to just try to clean it.
Broken solenoid valve or fuel jet of the idle system
First of all, you need to look at the position of the fuel jet and solenoid valve. As a result of some kind of breakdown, it can turn away, which is why the breakdown occurs. Just turn it on. Also try removing the wire from the valve and putting it back on. You should hear a characteristic click. It indicates that the valve is working. If you do not hear a click, then connect the battery positive and the valve terminal. If you do not hear a click, then the valve will need to be replaced. If there is a click, it is worth checking the EPH system.
The serviceability of the valve can be checked by removing the fuel nozzle from it. Examine it carefully. It should not be contaminated or damaged. Look at the O-ring and the locking needle. The jet should be thoroughly cleaned and blown out with compressed air.
This is a very broad problem that will be difficult to fix. It doesn't always cause the car to stall. This can happen if the fuel mixture is very lean with excess air. This is the reason why the carburetor in the VAZ 2107 starts and stalls. In this case, you need to check the entire carburetor.
Particularly susceptible:
- Ring under the valve;
- Tube to vacuum tube;
- Tube to valve cover;
- Quality screw ring.
Sometimes it will be easier to replace the entire carburetor.
Trigger diaphragm damaged
If the reason is the trigger diaphragm, then it will have to be completely disassembled and inspected. Sometimes it may be necessary to completely replace the starter, but not often. It will need to be adjusted. Be sure to replace the diaphragm with a new one.
Clogged fuel and air jets
Emulsion wells and dosing system tubes may also be clogged.
You will need to disassemble the carburetor, remove the above parts and clean them. To clean, you need to use acetone, a brush and a can of compressed air. They must be cleaned of all visible contaminants. It is worth noting that in Solex and ozone systems the components will be the same. Only their location differs.
Cleaning requires:
- Air jets;
- Emulsion tubes;
- Fuel jets;
- Emulsion wells.
All components need to be cleaned, even if some of them are not very dirty. This will help avoid repeated breakdowns.
Clogged fuel and air jets of the idle system
Clogging of these areas of the carburetor can also cause the VAZ 2107 to start and immediately stall. In this case, you will have to disassemble them. This is quite easy to do, you just need to carefully unscrew the jets. Next you need to clean them and blow them with compressed air. Sometimes they may need to be replaced. You can try cleaning the jets without completely disassembling the carburetor. This will significantly reduce cleaning time.
The fuel level in the float chamber is broken
This is a very common reason why the carburetor stalls in a VAZ 2107. This is due to improper adjustment of the fuel level. The fact is that the fuel mixture is disrupted. It can be highly enriched, or vice versa, depleted. In this case, adjustments need to be made. It may take a long time, but this way you can avoid carburetor malfunctions.
Choke not adjusted
Because the choke may not be fully open, the fuel may become richer. Most often this does not lead to serious problems, but sometimes the fuel becomes so rich that the engine is very difficult to start. Especially if it has been heated by long driving. In this case, it is worth adjusting the air damper (suction). Sometimes a highly enriched mixture can even flood the candles.
If the air damper is working correctly, it should cover the cross section of the right chamber. This occurs when the handle is fully extended. And if the handle is recessed, then it should stand vertically. If this does not happen, then the cause of the carburetor breakdown is precisely the incorrect adjustment of the choke. Adjusting it shouldn't take you much time.
Other reasons why the VAZ 2107 stalls
A VAZ 2107 may stall not only because of the carburetor. This may occur due to failure of other systems. First of all, pay attention to the ignition system. Its failure can often be confused with a carburetor failure. This is because the symptoms of a faulty ignition system are very similar to the signs of a faulty carburetor. You also need to check the power system. It may also be the reason why the VAZ 2107 starts and immediately stalls.
conclusions
Most of the above causes of breakdowns can be eliminated yourself. To do this, you just need to strictly follow the instructions. Most often, you just need to clean some parts of the carburetor, but sometimes you may need to completely replace the carburetor in a VAZ 2107. This way you will quickly get rid of many problems associated with the fact that your car starts and immediately stalls.
