One of the problems that a car enthusiast who owns a domestic VAZ 2109 may encounter is that the carburetor stalls while driving. A large number of articles are devoted to this topic, but real experience will allow you to solve the problem faster, since there are several reasons for this.
So, professionals who had experience solving the problem of a VAZ 2109 with a carburetor engine stalling at idle found several reasons and ways to solve them.
Causes and solutions
When the VAZ 2109 carburetor stalls at idle, that is, when your foot is on the gas pedal, the car works flawlessly, and as soon as you lower it, it stalls, you should look for the cause in the idle speed solenoid valve. To find the reason, you need to understand the meaning of the machine. Thus, the carburetor of the car has an idle system, which consists of a fuel channel with a nozzle, an air channel and a solenoid valve. When the car is idling, fuel moves through a special idle passage into the engine. To ensure that the car operates at idle speed, there are holes on the nozzle.
What kind of malfunction causes the idle speed to disappear?
There may be two reasons:
- Problems with fuel supply at idle.
- There is an air leak in the system, which disrupts the optimal proportion of air and gasoline in the combustible mixture.
In the first case, the responsibility falls on the idle air solenoid valve. If it malfunctions, fuel will not be able to flow into the engine.
To eliminate the cause, you should remove the air filter, from which the cover is then removed. After this, a mini service check is carried out. With the ignition on, remove and place the chip on the valve. The serviceability of the coil is indicated by characteristic clicks that are heard during manipulations. But to be completely sure of serviceability, you should unscrew the valve. To do this, use key No. 13. Then remove the jet and check for contamination. Blowing air through your mouth, see if it passes through it normally. After such a check, you need to close the hole in the EAC (hereinafter the idle speed solenoid valve) with your finger and turn on the ignition. This procedure will blow out any debris that has accumulated in front of the fuel jet, if there is any there.
You should also check the integrity of the rubber seal. If there is damage, deformation or a loose fit, air will be sucked in, which is why the machine will malfunction when idling.
If there is no characteristic click when removing and putting on the chip, then you should check whether there is voltage. If it is missing, you should check the carburetor throttle economizer.
If there is voltage, but there is nothing to replace the valve with (the breakdown occurred on the road), then you can take emergency measures that will allow you to complete the route. To do this, you need to remove the nozzle and break off the plastic needle and put the nozzle in place. In this case, there is no need to put a wire on the EPHH.
Solution methods
Once the main reasons why the VAZ 2109 engine fails are identified, you can proceed directly to methods of diagnosing and troubleshooting problems. It is worth recalling that for a complete diagnosis you will need certain tools, as well as design knowledge of the power unit.
So, what tools will you need: a set of keys, heads and screwdrivers, a hammer, WD-40, a multimeter, as well as new spare parts that have become unusable. Now that everything is at hand, you can proceed directly to the repair process.
Poor quality fuel
The engine often jerks and tripping occurs because low-quality fuel enters the combustion chambers. This is typical for the CIS countries, especially Russia and Ukraine, since most gas stations dilute gasoline or sell it of low quality.
So, low-quality fuel, in addition to clogging the fuel lines, also, when it gets into the combustion chambers, does not form a normal air-fuel mixture, and therefore the car begins to twitch and jerk, in the worst case, black smoke and shots will come from the exhaust pipe. This means that the gasoline is not the best and should be replaced.
To eliminate the malfunction at this stage, you will have to clean the fuel supply elements, such as the fuel tank, gas lines, injectors and the fuel filter element (which is most likely clogged).
Fuel pump and gasoline filter element
Even if the fuel that enters the engine and its systems is of fairly good quality, you do not need to be sure that the fuel supply elements will not fail. The second reason why a car starts to run poorly is a malfunction of the fuel pump.
To be more precise, interruptions in the operation of such an important element lead to an uneven supply of fuel to the engine
Causes of the problem
Quite often, VAZ 2109 owners are faced with a problem when the carburetor does not hold speed while idling, and the engine simply stalls. There can be many reasons, and they are all united by a number of characteristic features.
The first reason is a clogged idle jet. Even though the fuel supply system has 2 filters (coarse and fine), even one speck may be enough to clog the nozzle.
fine filter
Also, the fine filter itself may become clogged. This often happens when the filter was not replaced with a new one in time. Less commonly, malfunctions in the idle system occur.
There is no difference at all between the symptoms for any of the causes of the problem. Determining what exactly needs to be cleaned or changed can only be done through a visual inspection or diagnostics.
Also, sometimes the revs not only disappear completely, but also float. At the same time, the VAZ 2109 car does not stall. In this case, to the above reasons, you should add: a faulty solenoid valve or idle speed sensor.
Common causes of engine stalling at idle
Separately, the most common problems leading to engine failure without an applied load should be described.
The idle speed controller is faulty
The problem is typical for injectors and modern internal combustion engines. A smart unit often fails due to mechanical damage, natural wear, or incorrect calibration.
The electronic regulator has several weaknesses:
- signal sensors;
- control relays;
- fuse system.
Throttle valve dirty
A sensitive throttle often becomes the reason for visiting a service station. In the idle position, the damper on most designs opens only partially. When carbon deposits appear on the surface of the valve, the passage opening decreases. The negative effect reduces the idle speed or may cause engine failure.
To fix the problem, just clean the mechanism and put it back in place.
Idle fuel jet clogged
Frequent breakdowns in carburetor engines. The fuel jet is a screw with a thin hole drilled inside. If low-quality fuel is used, or rust appears in the gas tank, the line becomes clogged, which prevents the free passage of liquid.
Fuel pump malfunctions
The engine behaves similarly when this part wears out or malfunctions. When the internal combustion engine is idling, the working part of the unit rotates slowly, the pressure in the fuel system is minimal. When the pump impeller wears out, its performance drops noticeably. The effect is especially noticeable at idle speed.
Fuel filter dirty
The following problem is common to all power plants, regardless of the design and type of fuel consumed. When the filter element is clogged, the throughput of the device is reduced to a minimum. An amount of fuel that is insufficient to maintain stable engine operation enters the combustion chamber.
Malfunction of the mass air flow sensor
The mass air flow sensor is responsible for reading and adjusting the supplied air flow. If the sensor transmits incorrect information, the ECU will not adjust the fuel mixture correctly. Consequently, the power unit will fill or lack gasoline.
Contamination of the crankcase ventilation system
It may become clogged due to the use of low-quality oil, fuel or lack of maintenance.
When excess pressure appears inside the crankcase, the system stops functioning normally, excess pressure is created in the engine and the internal combustion engine stops working.
Troubleshooting
In order to fix this problem, you need to determine the culprit. Once you have located the location where the problem occurred, you can begin preparing for the repair work. First of all, check whether the carburetor is set correctly. To do this, tighten the quality screw and the quantity screw until it stops, and then unscrew it as indicated in the factory settings of the carburetor (often, the carburetor settings are as follows: quality screw - 2.5 turns, quantity screw - 4 turns). If there are no changes, and the engine still does not idle, or even stalls, then you need to look for the reason, choosing from the above.
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.
- Press the handle of the fuel pump to pump gasoline into the carburetor float chamber.
- Place the gearshift lever in neutral position.
- 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.
- If the car starts, let it idle, release the throttle and take your foot off the clutch pedal.
- 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.
The engine stalls periodically
This phenomenon may be due to problems with the ignition system. When driving, chaotic interruptions with sparking on the spark plugs are possible, both on a specific one and on all of them at the same time. The lack of a spark will most likely lead to the unit stopping.
If a car stalls while driving and then starts (including the 2112 VAZ), the most common reasons include the following: malfunction and moisture in the ignition coil, damage to the crankshaft position sensor and ignition module, failure of safety elements of control systems sensors
In this case, you should pay attention to the condition of electrical wires and their connections, which may contribute to power outages
It is very rare for a car to stall while driving and then start again due to a faulty vehicle speed sensor.
Determining the quality of the spark
At this stage, you need to understand whether there is voltage on the spark plugs. To do this, just unscrew one spark plug and connect the central electrode to the high-voltage wire. Next, ensure that the threads are in contact with the ground of the car and turn on the ignition. A stable spark of blue (white-blue) color indicates that everything is fine with the ignition.
Check the remaining spark plugs in the same way. Because a common reason for an engine to fail to start is the failure of one of these parts.
After working for a while in this mode, the engine will stall.
Cylinders with non-functioning spark plugs are simply filled with too much gasoline and the situation will repeat itself when the engine is restarted. If there is a spark on all spark plugs, evaluate their color and size. Yellow/red color and small size also indicate that the car will start and subsequently stop working.
At this stage it is enough to replace the failed spark plugs
When purchasing parts, pay attention to the manufacturer’s recommendations regarding clearance and heat rating parameters
Optional equipment
As a rule, the stable engine speed of most cars is affected by turning on the air conditioning compressor. Very often this happens at low and idle speeds. Since the air conditioner consumes a considerable amount of energy, the control unit sends a signal to the power system to increase the volume of fuel mixture supplied to increase idle speed to compensate for the loss of power consumed by the air conditioner.
But when the impulse to turn on the air conditioner does not arrive at the electronic unit due to a communication failure between the computer and the device module, the control unit is not able to assess the situation and add fuel. As a result, the stability of idle speed is disrupted until the moment when the engine completely stalls.
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.
