Checking the fuel pump of VAZ 2108, 2109, 21099 cars

On a VAZ 2109, signs of a fuel pump malfunction can be considered a complete or partial cessation of fuel supply to the carburetor, which leads to the impossibility of starting both a cold and hot engine. It will first start and then stall; in addition, unstable idle operation is possible. If you think that the gasoline pump in the VAZ 2109 is not working, you will need to check it. This can be done on your own.

What is an injector - a modern replacement for a carburetor

An injector is a device that replaces the operation of a carburetor and consists of a fuel rail (rail) onto which injectors are attached. Under high pressure from the gasoline pump, fuel enters the rack, and from there the gasoline is distributed to the injectors. The injector nozzles, using rubber sealing rings, are inserted together with the rack into the engine block and inject fuel, which then ignites.

One of the main parts of the work in the injector is performed by the intake manifold. Its device includes a throttle valve, which is responsible for supplying air from the environment to the engine block.

An injector is a fairly thin device, the operation of which is constantly regulated by the electronic “brain” of the car. The presence of an on-board computer allows specialized car repair shops to carry out quick and accurate vehicle diagnostics. Diagnostics is carried out by connecting special equipment through a connector to the vehicle’s on-board computer.

Injection models of the VAZ 21099 since 2000 have also acquired electronic “brains”. This car model has front-wheel drive and shows high road stability. The engine of the injection 99 is four-cylinder, eight-valve, with a displacement of 1.5 liters. In a modern VAZ, the maximum speed indicated on the speedometer is 180 km/h. In practice, it is not recommended to accelerate this car over 160 km/h.

A design feature of a car injector is much lower fuel consumption compared to a carburetor car. VAZ 21099 (injector) has an average consumption of 7.0–7.5 liters per 100 km, at an average speed of 100–120 km/h. It was possible to achieve a reduction in fuel consumption by reducing the vehicle's energy consumption. It is worth noting that the injector of this car is not very picky about octane fuel and consumes the same gasoline, both A-92 and A-95.

Malfunctions of VAZ 21099 - the injector also fails!

Regardless of the time of year outside, very often the car may simply stop starting, or begin to respond poorly to the gas pedal. In this case, all on-board computer sensors may not show errors. The causes of failure should be sought in the injector.

Usually the breakdown is associated with clogging of the fuel injector nozzles, which increases fuel consumption in the car and reduces traction. Due to the fact that the fuel does not enter in the quantity required for engine operation, the idle speed begins to float. For a VAZ, the normal value when the engine is idling in warm weather is 900 rpm. When starting in the cold season, the engine produces 1500 rpm; with proper operation, after 5–10 minutes they should drop to 900.

It is also worth paying attention to the throttle valve of the intake manifold - over time, black deposits appear on it, which prevents it from properly passing air. It is enough to clean the damper with a special spray and gently wipe with a cloth - the problem is eliminated!

Gasoline supply problems - common symptoms

Malfunctions of the fuel supply system are conventionally divided into 2 categories:

In the first case, the engine does not start and does not engage the starter during rotation, that is, it does not show signs of life. In such a situation, it is always easier to determine the cause of the breakdown.

When insufficient fuel enters the cylinders, the following symptoms appear:

The cause of the above phenomena may be a malfunction of the fuel pump or other elements of the system, and the primary symptoms are almost the same. To carry out an accurate diagnosis, you need to understand how the car's power system works.

Repair of VAZ 21099 injector

In most cases, you can get by by simply cleaning the injector. This procedure can be done at every car service center. To prevent serious damage, have your car diagnosed in a timely manner. You can do the cleaning yourself using chemicals, but it will not be complete. If you decide to clean the injector yourself, you need to buy a repair kit for rubber O-rings for injectors and injector cleaning fluid.

Before performing this procedure, you need to remove the terminals on the battery and disconnect all power supply connectors near the injector. Then we proceed to remove the manifold, carefully unscrew and disconnect the pipes from it. After this, we release the pressure in the fuel rail of the injector by pressing the nipple on the left side of the rail.

Next, carefully move the sealing clamps from the injectors and, by swaying in different directions, remove our injector. It is not difficult to see whether the injectors are dirty. After disconnecting each nozzle, place them in a jar with a pre-prepared chemical mixture for 30–40 minutes. Once you have completed this procedure, we proceed to reassemble our fuel system in reverse order. Be sure to remember to change the o-rings on the injectors that come in the repair kit.

VAZ 2109 fuel pump malfunction, types of VAZ gasoline pumps

On a VAZ 2109, signs of a fuel pump malfunction are a complete or partial cessation of the supply of gasoline to the carburetor, this entails the inability to start both a cold and hot engine, it will start and stall, in addition, unstable idling is possible. If you suspect that the fuel pump in the VAZ 2109 is not working, then you should check it. It's not difficult to do it yourself, just read this article.

Design and operation of fuel supply

The system that provides the engine with the required amount of gasoline operates according to the following algorithm:

Reference. In various car models, 2 schemes are used for installing the RTD and laying the return pipeline - in the engine compartment or directly in the gas tank. In the first case, the standard fuel pressure in the system is 2.7...3.0 Bar, in the second - 3.8...4 Bar.

A common mistake made by ignorant car enthusiasts: if the combustible mixture does not enter the cylinders, then the fuel pump is definitely not working. Knowing the design of the fuel supply, we can assume other problems:

To accurately determine the source of the problem, you need to check the operation of the electric fuel pump and other elements. It is not necessary to go to a service station - diagnostic work can be carried out in your own garage.

Checking the fuel pump

• Let’s immediately look at the two most common types of gasoline pumps, “Pekar” and DAAZ. They are installed on both rear-wheel drive and front-wheel drive cars. To check the serviceability and functionality of the entire fuel supply system:
• Remove the gasoline hose from the outgoing (discharge) fitting of the gasoline pump
• Then press the fuel pumping lever manually several times
• If the VAZ fuel pump is working properly, then a powerful stream of fuel should come out of the fitting
• If there is no stream, or there is a weak stream, perform a second check

To check the serviceability of the intake valve:

• We disconnect the fuel hose from the suction fitting of the pump (it turns out that now we have removed both fuel hoses from two fittings)
• Then we plug the suction fitting with our finger and press the lever for manual pumping several times
• At the same time, you should feel a vacuum on your finger (it should be sucked to the fitting)
• When there is a vacuum, this means that the fuel pump is working, look for faults in the gas tank or fuel lines
• If not, the fuel pump on the VAZ 21093 does not work, remove the pump, disassemble and change the intake valve

To check the exhaust valve for leaks:

• Place your finger on the hole in the injection fitting (the one that supplies gasoline to the carburetor), then press the lever several times to manually pump
• At the same time, a very noticeable stream of air comes out of the fitting hole, it pushes the finger away from the fitting
• If the stream is weak or absent, it means that the fuel pump on the VAZ 2109 does not pump, then remove the pump, disassemble and replace the exhaust valve
• If the filter is deformed or clogged:
• Remove the cap from the fuel pump, take out the fuel filter, clean it, rinse it in gasoline, then blow it with compressed air
• If the filter is deformed, then change it
• In the Pekar brand fuel pump, as well as similar pumps, the filter is removed by unscrewing the suction fitting from the cover, so you don’t have to remove the cover itself
• In case of malfunctions (leaky, torn) of the diaphragm:

Common reasons

Injector/carburetor:

1. The fuel filter is clogged or deformed. It becomes clogged if low-quality fuel is poured (with impurities, rust, etc.). Remove the cap from the fuel pump, remove the filter, rinse with gasoline and blow with compressed air. It is also recommended to flush the fuel system. If the fuel filter is deformed, it must be replaced.
2. Kink in the fuel hose. This malfunction occurs during machine repairs and when installing units near the fuel system. In this case, the bend is eliminated or the hose is replaced.
3. Bent fuel pipe. Occurs as a result of mechanical damage to the bottom upon impact. As with the hose, we replace it if necessary.

Checking and adjusting pump pressure

It's no secret that any car part has a certain resource. So the “nine” fuel pump, like any part, eventually stops pumping gasoline properly, our instructions will help you figure it out:

• Moreover, on the VAZ 2109 the problems with the fuel pump are always the same
• As a rule, the reasons are not tightness of the valves or housing, fuel wire, or diaphragm, perhaps the fuel filters are clogged, or the fuel supply lines are overheating
• The main problem is ultimately insufficient gasoline pressure at the outlet of the fuel pump.
• And in the case when your fuel pump initially could not show the appropriate (required) output pressure, then all the problems stated above only aggravate the situation
• You need to know exactly the output pressure (immediately before the carburetor) that the fuel pump should develop when the engine is idling.
• As a rule, all fuel pumps - both cars and trucks - must produce a pressure in the range from 0.20 atmospheres to 0.35 atmospheres. When your gas pump has a similar output pressure, then you should not have problems with gasoline supply
• The pressure is measured with a pressure gauge that has a scale with divisions of 1.6 atmospheres - on such a pressure gauge it will be possible to record the pressure of the fuel pump
• When the pressure is measured and it turns out to be below normal, you may just need to adjust the pump
• It is possible to adjust the fuel pump either by moving it closer or further from the engine block (by changing the thickness of the gasket)
• The second method is to strengthen the spring (washers are placed under it, the operation is performed taking into account the wear of existing parts and the strength of the spring)
• The third option is to change the length of the rod
• Any of the listed measures (or all in combination) make it possible to increase the pressure of the fuel pump to the level of 0.20 - 0.30 atmospheres
• The best thing, of course, is to bring the figure to 0.30-0.35 atmospheres at idle speed
• When the engine starts running at higher speeds, this figure will increase a little more.

Characteristics of the VAZ 2109 fuel pump

To understand how a working pump works and check its operation, it is important to know its operating characteristics:

• The length of its rod is 82.4 millimeters
• In this case, the rod protrudes above the gasket by 0.8 - 1.3 millimeters
• The thickness of the very first gasket is 0.3 millimeters
• And, the stroke of the rod is 2.5 - 2.8 millimeters

The car won't start, but when you turn the ignition key you can't hear the fuel pump running? Don’t rush to replace it with a new one; it’s better to first find out how to check the operation of the gas pump yourself.

Procedure : 1. Check the fuel pump fuse. This is where you should start checking the fuel pump. On a VAZ 2110 it is located near the left foot of the front passenger.

2. How to check the fuel pump relay. The relay is located next to the fuse, so let's check that right away. We check the voltage at the control terminals one by one (87, 86 and 85 in turn), and touch the ground with the other end. The testing tool can be a multimeter or a test lamp with a current consumption of no more than 0.25A. If the lamp does not light and the fuse is good, then we check the wiring and serviceability of the ECU.

Sometimes they check differently, for example, instead of a relay, they connect a test lamp between pins 85 and 86. When the ignition is turned on, the lamp should light up. You can also place a jumper between pins 87 and 30. Does the fuel pump start when you turn the key? This means the relay is faulty. You can also check the fuel pump relay by replacing it with a known good relay.

3. How to check if the fuel pump is working. Without removing it, we check the voltage on its chip using a test lamp or multimeter.

How to check a removed fuel pump . To do this, apply +12V. (for example, from a battery) to the contacts of the fuel pump. Be careful; residual gasoline may ignite from a spark when connecting the contacts.

4. The alarm system is to blame for the operation of the fuel pump. If the car falls into a hole, then after a strong impact the “Valer” button is activated, which blocks the operation of the fuel pump.

A buzzing sound from the fuel pump does not mean it is working, you should check the fuel pump pressure first.

Where is the fuel pump relay located?

Where is the fuel pump relay located? The installation location of the relay varies depending on the make of the car. Most often, it is located under the hood, in the fuse and relay box.

The fuel pump relay is designed in the circuit to prevent accidental application of high voltage to the fuel pump winding. The relay is standard and consists of a plastic body and coils with contacts. It is located in the car interior near the console. To access it, you need to remove the protection cover.

In appearance, it is a small box that resembles a “plug” with an American type of output. Each terminal has a marking that indicates the following: 31 – mass; 30– +12V constant (regardless of ignition); 15– +12 with the ignition on; 50– +12 when the starter is running; TD – signal from the ignition system; TF – engine temperature signal from the injection control unit KE. Outputs: 87 – supplies power to the fuel pump; 87H – oxygen sensor heating; 87V – turns on the starting injector.

But sometimes the fuel pump does not turn on when the key is turned in the ignition. With what it can be connected? First of all, the fuse, although if it had blown, it would not work at all. Maybe the contact is bad?

It’s easy to check the functionality of the pump itself, so we do this:

1. remove the protective casing, under which there is a block with relays and fuses;
2. we unscrew the fastenings of the block, remove it, it remains attached to the wires;
3. we pull the RB out of the block, place a jumper between two opposite contacts, thus directly supplying power to the BN;
4. if with such a connection the electric motor of the pump begins to make noise, it means that the BN itself is working, most likely the fault is hidden in the relay;
5. if there is no voltage on any of the contacts on the RB block, you should look for a break in the wiring; there may also be poor contact at the place where the wire is attached to the terminal.

Restoring the fuel line and replacing the fuel pump VAZ 2109

The VAZ 2109 fuel pump is an important component of the car. He is responsible for transporting gasoline along the fuel line from the gas tank to the engine compartment. The VAZ 2109 fuel pump injector is an electrical device, while in the carburetor version this element is mechanical.

Often the fuel pump is the reason the engine fails to start. The fuel injector or carburetor does not receive fuel in the required quantity, and the “nine” simply does not start. To understand the cause of the malfunction, you need to know the design of the pump, check all parts of the fuel pump for integrity and functionality.

Using a pressure gauge

If in the event of a malfunction with the electrical supply of the fuel pump, everything is clear - either it works or not, then mechanical wear is more difficult to determine. There are several techniques for this.

The fuel pump may be faulty for two reasons - mechanical and electrical.

You can estimate the fuel pressure if you unscrew the fuel rail plug and drain gasoline from the spool. There should be a powerful jet. Next, we unscrew the spool itself and connect a pressure gauge, preferably a fuel one, but you can also use one that measures the air pressure in the tires. Turn on the ignition and see how much the pump has pumped. It must be at least 280 kPa, on some models 380 - 400 kPa. To make it clearer, this is 3.8 - 4 kgf/cm2.

Checking the pump on the injection "nine"

The VAZ 2109 with an injection engine has an electric pump. It is powered by receiving voltage (12 V) from the battery. Its location is directly in the Lada gas tank. The mission of the electric pump is to deliver gasoline to the fuel rail under high pressure. Next, the fuel from the ramp enters the nozzles, which inject it into the combustion chamber.

If the injector on a VAZ 2109 does not pump the fuel pump, check the following elements:

• fuel pump relay VAZ 2109;
• fuse;
• voltage to the pump;
• wires from the mounting block to the pump;
• pressure in the fuel rail.

A working fuel pump should start working when the engine starts. The sound of its operation should be heard under the rear seat. We begin the first stage of verification.

Possible situations and your actions

We take a voltage indicator and check the serviceability of the relay and fuse, which are located in the mounting block.

If the electrical circuit connection diagram is in order, you need to check the voltage supply directly to the pump. To do this, we dismantle the rear seat of the Lada 2109 car. Under it there is the top cover of the pump and the connected wire connector from the mounting block, and the fuel line hose is also supplied here. We disconnect the contacts and unscrew the bolts on the cover.

Now you have direct access to the pump. We remove the fuel pump from the gas tank.

We measure the voltage at the fuel pump using a multimeter (tester) or a 12-volt light bulb. If the device shows that voltage is supplied to the VAZ 2109 fuel pump, the problem is not electrical. This means that the fuel system should be checked. Well, if there is no voltage, you don’t have to worry about the pump malfunctioning. Just check the integrity of the wire leading from the mounting block to the pump for damage.

On a fuel-injected "nine", the fuel level in the gas tank should be maintained at least 10 liters. This is done to ensure that the fuel pump does not suck in air under any circumstances. We check the serviceability of the pump by measuring the pressure in the fuel rail.

We connect the device to a special hole in the ramp. If the voltage is normal and the pressure gauge shows no pressure, the problem may be in the fuel filter. We check its integrity and throughput. If the filter is working properly, we check the fuel line leading from the gas tank to the ramp.

If all these parts are in good working order, we conclude that the fuel pump itself has failed. Having replaced the pump with a new one, we connect it and try to start the car. If the car starts, the problem really was in the pump. If the engine fails to start, the fuel system should be checked more carefully.

In the absence of a pressure gauge, the performance of the gasoline pump is checked by the amount of gasoline pumped per unit of time.

This check can be performed by connecting a hose to the ramp and lowering it into a container. We wait and let the fuel flow into the container for one minute. Then we check the volume of fuel in the container. It should be from 0.5 to 1 liter.

Electrical diagram of VAZ 2110 features

Each VAZ-2110 car is equipped with electrical equipment, which is designed to ensure its operation and create comfortable conditions for the driver and passengers. All electrical appliances are integrated into a single network. To understand its composition and order of operation, an electrical circuit diagram of the VAZ-2110 was created. The on-board DC network has a voltage of twelve volts and includes energy sources and consumers, protective and distribution devices, wires and switching elements.

Current

The car has two sources of electricity - a battery and a generator. The first ensures the functioning of systems before start-up, during start-up and in some engine operating modes. The second is the main one and serves both to power all consumers and to charge the battery. The electrical circuit of the VAZ-2110 is designed in such a way that the power sources ensure energy balance in the system.

Motor

For the operation of the vehicle's power plant, timely supply of the fuel mixture and its ignition in the engine cylinders are necessary. On a modern car, this function is provided by the injection system. The electrical circuit of the VAZ-2110 (injector) allows you to correctly connect its two main components: the fuel distributor and the ignition control system. The injection is controlled by a special electronic unit. An uninterrupted supply of gasoline is ensured by an electric pump. It is installed directly in the fuel tank. The electrical circuit of the VAZ-2110 fuel pump is designed to meet fire safety requirements

Important note: Some brands of cars may have two fuel pumps installed. Previous VAZ car models used a carburetor fuel supply system. It is somewhat outdated, less economical and reliable

The electrical circuit of the VAZ-2110 allows you to connect a modern injector instead of the previous system without modifications. To change the fuel supply option, you must contact a specialist. For the engine to operate, its temperature must be maintained within the operating range. The cooling system is used for this purpose. It includes a fan and a number of sensors that operate on DC power.

It is somewhat outdated, less economical and reliable. The electrical circuit of the VAZ-2110 allows you to connect a modern injector instead of the previous system without modifications. To change the fuel supply option, you must contact a specialist. For the engine to operate, its temperature must be maintained within the operating range. The cooling system is used for this purpose. It includes a fan and a number of sensors that operate on DC power.

Exploitation

A car is more than just one smoothly running engine. To operate this type of vehicle, lighting, alarm, safety systems (active and passive), sound signal, and windshield wipers are vital. This list can be continued. All named devices are consumers of electrical energy. There are hundreds of them in a modern car from the Volzhsky plant. And any of them can fail for various reasons. The electrical circuit of the VAZ-2110 allows you to diagnose and eliminate any fault that may arise, and replace electrical wiring elements. Modern traffic rules prohibit the operation of vehicles if the above electrical devices do not work.

Comfort

The electrical circuit of the VAZ-2110 includes a number of devices that perform a service function. That is, they provide minimal comfort for the driver and passengers of the car. These are air conditioning systems, interior lighting, also a cigarette lighter, power steering, and radio. Cars from the Volzhsky plant are not famous for their increased comfort. However, the electrical circuit of the VAZ-2110 allows for some modifications, that is, tuning. To carry out this work, the help of a specialist is required. The vehicle wiring is reliably protected by a fuse block (inserts). It is they who, when shorted, do not allow all the wiring to burn out. Use only original products of the specified power. Keep some spare fuses with you. If any electrical appliance fails, first check the serviceability of the fuse links. In most cases, replacing the fuse will resolve the problem. That's all the information we wanted to share

We thank every reader for your attention.

Malfunctions of the pump with carburetor

Repairing the VAZ 2109 carburetor fuel pump should also begin with diagnostics. But in this regard, there is a significant difference from the injection version of the car. It lies in the fact that the fuel pump, in this case, is mechanical. The principle of operation, and therefore the repair, is different. Diagnosis involves the following basic steps when checked:

• general condition of the fuel pump;
• intake and exhaust valves;
• tightness;
• filter for clogging or damage;
• pump diaphragm;
• pusher

VAZ mechanical fuel pumps come in two types: DAAZ and Pekar. The principle of operation is similar, there are slight differences in design. The main parts of all mechanical pumps are: inlet and outlet valves, fittings, pusher, diaphragm and rod.

To check the inlet valve, you need to disconnect the hose from the suction fitting. Close the fitting with your finger and pump up the pump manually. If the finger is attracted to the valve, everything is in order - this part is serviceable; if not, the valve must be replaced. The outlet valve is checked by unscrewing the discharge fitting. By placing your finger in the same way and pumping up the lever, you should feel pressure.

It happens that the filter mesh is clogged. You need to take out the filter, clean it, wash it and blow it with compressed air. In case of obvious deformation or damage, the fuel pump mesh is replaced. If the fuel pump leaks or gets hot, the sealing diaphragms are most likely damaged. To replace them, remove the pump cover and unscrew the nut that holds the rod. Next we remove the diaphragms. In the case of the DAAZ pump there are 3 of them, while Pekar has one.

Checking the pump characteristics

As you can see, the main reasons for a non-working fuel pump are valves, filters, hoses, and diaphragms. At the outlet we get insufficient pressure. How to measure this pressure, and within what limits is the norm? Firstly, you need to know exactly the nameplate value of the output pressure to the carburetor of your car at idle speed. Approximately the indicator should vary from 0.2 to 0.35 atm.

Measurements are carried out using a pressure gauge with a division value of 1.6 atmospheres. If the pressure is not much less than normal, replacing individual parts may help solve the problem. But if there is a significant deviation, the VAZ 2109 fuel pump will most likely need to be replaced. Timely maintenance and rational use help to avoid this.

In addition to the pressure indicator, in order to repair a part, you should know the characteristics of the pump itself. If the linear parameters have changed, the tightness and stability of the entire mechanism may be impaired.

The rod must have a length of 82.4 mm and protrude above the gasket by no less than 0.8 mm and no more than 1.3 mm. The thickness of the closest gasket is 0.3 mm. The stroke of the rod should be in the range from 2.5 to 2.8 mm.

Fuel pump VAZ 2109: how the injector works. Replacement and inspection

You will need to consider the features that the VAZ 2109 fuel pump has. If the injector is in the fuel injection system, then the pump is of an electric type. Its use is due to the need to control the fuel supply to the combustion chambers. But, as you know, gasoline first enters a special ramp, in which it is mixed with air in a certain proportion (14 to 1). It maintains constant pressure, with the help of which the mixture is supplied to the combustion chamber through holes in the electromagnetic injectors. These are devices that transform the air-fuel mixture into very small droplets. Essentially, the mist in which the gasoline is suspended in the combustion chamber is ignited.

Purpose and principle of operation of the fuel pump

The fuel pump is designed to pump fuel from one point to another. In a car, the role of the first point is played by a fuel reservoir - the tank, and the second - by the engine, where the pumping takes place. This process occurs at a certain pressure, which is maintained by the pump reducer, which is a very important point.

Fuel pumps are divided into 2 types according to the type of drive: electric and mechanical. Inside the first there is an electric motor with a mini-pump, which operates from the mains and uninterruptedly pumps fuel into the engine. The second type is becoming increasingly rare, as it is installed on carburetor cars, and operates due to the reciprocating movement of the lever.

How does a fuel pump work?

There is nothing complicated about the fuel supply system. A conventional pump, which is driven by the rotor of an electric motor. To protect the entire fuel system from small particles, a filter is used. But this is not the end of the features, because it is worth noting that it is necessary to maintain the pressure in the ramp at the same level. And the VAZ 2109 fuel pump (the injector simply cannot work without it), provided that it constantly pumps gasoline, will begin to pump up the pressure higher and higher. And this will disrupt the operation of the system.

Therefore, it is necessary to adjust the pressure. For this, a special device is used, which is called a pressure regulator. It is installed in the fuel rail and connected to a pipeline that serves to dump excess gasoline into the tank. When the ignition is turned on, the rail pressure sensor is polled, after which the fuel pump drive is turned on. After the pressure in the rail has increased to the required value, the fuel pump is turned off. Therefore, it does not work all the time.

Causes of the problem

As a rule, if the fuel pump does not work when you turn on the ignition, experts recommend paying attention to the power supply. Most likely, it does not go to the fuel pump, and it does not pump fuel

The connection diagram for the fuel pump on most modern car models looks like this: the negative and positive wires are connected to the element, as well as the wire for the VCT (an indicator of the amount of fuel).

Fuel pump does not work when ignition is turned on

The presence of power to the fuel pump is checked as follows: power is supplied to the 12V light bulb from the external connector of the device. The indicator should light up after turning the ignition key. Otherwise, if this does not happen, there is an open circuit in the external circuit.

On the contrary, if the indicator lights up and the fuel pump itself does not work, this gives reason to begin diagnosing the internal contacts of the device.

How to remove the fuel pump

The VAZ 2109 fuel pump is located under the rear seat. The injector implies its installation directly in the tank. The thing is that the pump is a submersible type. In the same unit there is a float-type fuel level sensor. It works due to the fact that the float moves the slider using variable resistance. At the same time, the current in the power circuit changes. The amount of gasoline remaining in the tank is determined by the magnitude of the change. To remove the pump you will need to use pliers, screwdrivers and an 8mm wrench.

It is quite possible that the reason that fuel is not supplied is a non-working VAZ 2109 fuel pump relay. The injector contains it, as well as a fuse, which could easily burn out. Before starting work, thoroughly clean the entire cover so that after removal no dust gets inside the tank. Then, using a screwdriver, loosen the clamps that secure the hoses. Remove them; if you can’t do it with your hands, try gently squeezing them with pliers and twisting them. After this, use a size 8 wrench to unscrew all the nuts that secure the lid to the tank body. Please note that there are washers there. Don't lose them. That's all, now the pump can be easily removed for replacement or repair.

how to replace it yourself

VAZ 2101 fuel pump rod: replacement and signs of breakdown

Fuel pump "nine"

Probably all owners of domestic cars have encountered a situation where the car cannot be started after some inactivity. The battery is working properly, the starter vigorously cranks the crankshaft, but the engine does not want to start.

This can happen for 2 main reasons: either there is no spark, which means that the ignition system does not work, or the combustible mixture is not supplied and, accordingly, the engine power system does not work.

We will talk about malfunctions of the fuel supply system. Let's consider a situation when the engine does not start because the VAZ 2108-15 fuel pump does not work. We will also learn how to replace the fuel pump of a VAZ 21099 car with your own hands.

Malfunctions, removal and repair of a mechanical fuel pump

On VAZ 21099 cars, the carburetor was equipped with mechanical diaphragm-type fuel pumps by the manufacturer. The main malfunctions of this type of pump are associated with rupture of diaphragms, breakage of the rod, spring and depressurization of valves.

The main advantage of mechanical fuel pumps is that they are easy to repair. If any element fails, you can buy a domestic repair kit at the nearest spare parts store and replace all faulty parts within an hour. The fuel pump on VAZ 2108-99 cars with a carburetor fuel supply system is located in the engine compartment, in the same place where the ignition distributor is located.

Removing the mechanical fuel pump.

First, open the hood and remove the negative terminal from the battery.

Then loosen the clamps and disconnect the fuel hoses from the pump pipes

After this, unscrew the 2 nuts securing the fuel pump and carefully, so as not to damage the gaskets, remove it

Pump device

Now it needs to be disassembled.

Unscrew the bolt on the top of the pump cover and remove it along with the strainer. Unscrew the 6 screws and separate the upper and lower parts of the case

Carefully remove the diaphragms along with the spring and rod, turning them 90°

After disassembly, it is necessary to carefully inspect all parts and replace damaged ones. Reassemble and install the pump in reverse order.

Electrical faults and replacement

Submersible electric fuel pumps were installed by the manufacturer on VAZ 21099 injector cars. Unlike their mechanical counterparts, these units are not dismountable, so they cannot be repaired. Mostly, such fuel pumps break down due to overheating and the use of low-quality fuel. In addition, very often faults arise not in the unit itself, but in its wiring.

If the electric fuel pump on your car hums and stops pumping fuel, you first need to check the serviceability of the electrics. Perhaps the wiring has shorted, the fuel pump relay has broken, or the fuse has simply blown. If the electrical is OK, the fuel filter needs to be replaced. If this does not help, then you need to change the pump itself. Please note that the VAZ 2108-15 electric fuel pump is located in the fuel tank, so to replace it you will have to crawl under the car.

The procedure is as follows.

1. First, drive the car onto a pit or lift.
2. Then remove the negative terminal from the battery.
3. Then remove the back seat and find the place where the inspection hatch is located. Unscrew the screws securing its cover and move it to the side.
4. Disconnect all wiring terminals from the fuel pump and fuel sensor.
5. Unscrew the nut securing the fuel supply pipe and move the pipe itself to the side.
6. Find the drain pipe fitting under the bottom and unscrew it.
7. Next, remove the gas tank.
8. Unscrew the fuel line tip nut and disconnect it from the fuel pump.
9. Unscrew all fastening nuts, remove the sealing ring and remove the electric fuel pump together with the storage cup from the fuel tank.

Reassembly must be done in reverse order.

Note: to prevent gasoline from spilling out of the fuel lines, after the 4th operation you can connect the battery and start the engine. After 4-5 minutes, the engine will exhaust all the gasoline remaining in the system.

Checking the pump's functionality

It is easy to check the VAZ 2109 fuel pump even without special instruments. The injector will not be able to operate without pressure in the fuel rail. Therefore, you need to keep the pump motor spinning. It’s easy to check; just connect its terminals to the battery. If you are afraid, then turn on an incandescent lamp in the gap of one wire. It will help determine the health of the motor winding. Please note that the filter must be as clean as possible. If it is clogged, be sure to change it. Otherwise, the pump will not be able to create the required pressure.