How to check a fuel pump: measuring pressure and troubleshooting it yourself

Causes: fuse, relay, connector

The pump power circuit includes many elements: closed relay contacts 5, fuse 3 (15 A), “+” wire, “pump-to-ground” wire. The most “difficult” defect is a short circuit of the “+” wire to ground. By the way, the cord itself is laid on metal, so such a defect cannot be ruled out.

Mounting block for dashboard

Both the relay and the fuse are located in a block located under the dashboard on the right. A fuse can blow in two cases:

• The “+” cord makes contact with ground;
• The motor resistance decreases due to overheating.

The first defect may be “floating”, and then it will be difficult to identify. But before calling an electrician, try checking everything else:

• Relay 5 should click twice: when the ignition is turned on and after 1.5 s. If this does not happen, replace the relay;
• Check fuse 3. If it is blown, you need to look for the cause.

Consider the situation: the relay is working, but the fuse is blown. Then we do this: disconnect the pump connector, install a new fuse and measure the voltage at the terminals. Details are below.

Connectors under the hatch, disconnecting them

You need to remove the hatch under the rear seat: two screws are unscrewed with a Phillips screwdriver. Next you need to disconnect the connector on the module, and then move on to the block under the dashboard.

First, turn off the fuel pump!

Replace the fuse. Let's move on to the fuel pump: connect the probe (zero cord) to any of the mounting studs. Voltage should appear on the “gray” wire when the ignition is turned on. And also check the potential difference between the “gray” and “black” wires - it should be equal to 12 volts, and also at the moment the ignition is turned on. Wiring:

• The two outer cords are the FLS sensor;
• “Black” – minus power supply;
• "Grey" is a plus.

The "black wire" sometimes loses contact with ground. At the last step, we checked exactly this version.

There are reviews from owners that say: the fuel pump on a VAZ-2112 does not work if the electric motor is working properly and there is voltage in the connector. This happens when the contacts of the internal terminal block oxidize (see photo).

Internal connector - yellow

Getting to the connector on the motor is not easy - you need to remove the fuel pump module by unscrewing 8 nuts around the perimeter.

Diagnosing the fuel pump

Safety precautions

Before unscrewing the nuts, you need to disconnect the two hoses. But first try starting the engine. The power supply to the fuel pump is not connected.

Please note - the power is turned off here!

Everything is ready for dismantling if:

• External connector is disabled;
• It is impossible to start the engine, although the on-board network is not de-energized;
• It is better if the tank is filled less than 50%!

You need to unscrew two fittings from the module cover (top photo). Then use a socket wrench to unscrew the nuts from the studs and remove the retaining ring.

There is very little left to the internal connector

Having gained access to the internal connector, you need to clean its contacts. Assembly is carried out in reverse order. Good luck!

Oxidation of the terminals of the internal connector is a typical disease of the VAZ-2112 fuel pump, and only one of the contacts does not work. The “+” terminal is more often oxidized.

Replacing an electric fuel pump on a VAZ

1. Reduce pressure in the fuel supply system.
2. Using the fuel supply hose tip clamp, disconnect 2 hoses in turn.
3. Unscrew the 8 nuts around the circumference of the clamping ring and remove it.
4. A wire with negative polarity is attached to one of the nuts; it must be removed carefully.
5. We take the electric pump block out of the fuel tank, tilting it slightly, to keep the fuel level indicator sensor lever intact, otherwise it will produce incorrect parameters.
6. Remove the sealing rubber ring of the fuel block. If its properties are lost, the product must be replaced.
7. Install the pump in reverse order.

When installing fuel hoses, focus on the direction of fuel supply indicated by the arrows, and the installation arrow on the electric pump cover should point towards the rear of the car!

Advantages of injection models

The main function of the pump is to supply fuel to the combustion chamber. It must meet certain requirements. The main criterion is pressure.

The pumps for injection and carburetor engines are different. Thanks to the engine with direct fuel injection, there is no need for preliminary preparation of the combustible mixture. As you know, the carburetor is the weak link. Difficult adjustments, clogged jets, difficult starting in cold weather create inconvenience for owners of classic VAZ brands.

Tens and VAZ-2112 internal combustion engines have significant advantages. Let us note the advantages of injection units:

• support for environmental standards;
• direct injection into the combustion chamber;
• fuel economy;
• system reliability;
• increased engine power;
• starting a cold unit without warming up;
• dispensing a portion of the mixture;
• The fuel module is controlled electronically.

Unfortunately, the injector has a number of disadvantages. Maintenance and repairs have to be carried out at a service station. It also requires qualified personnel and a computer to determine the malfunction of electronic components. Let us point out other disadvantages:

• design complexity;
• high requirements for the octane number of gasoline;
• complex diagnostics and repairs;
• expensive spare parts and equipment.

How do fuel pump breakdowns manifest themselves?

We will not consider a broken relay or a blown fuse as a serious reason. Sometimes the relay itself is enough to be removed and inserted into place, and the system will work; the contacts are simply oxidized, and the fuse needs to be tested with a tester and, if necessary, replaced with a similar one.

A much less pleasant situation is when the coarse filter, which is located in the fuel module along with the pump, becomes clogged. The symptoms of a breakdown are floating, so it’s quite difficult to immediately understand what needs to be done. The first signs of a clogged coarse filter:

• reduction in engine power;
• lack of traction at high speeds;
• Unstable engine operation at low and idle speeds;
• Difficulty starting the engine.

Signs of a fuel pump malfunction

Using these signs, you can determine that the fuel pump is not pumping.

1. The most common sign of a faulty fuel pump is that the car drives intermittently. While driving, the car begins to sharply slow down and then accelerate. Uniform movement of the vehicle is ensured by a continuous supply of fuel.
2. The second most common symptom is floating engine speed at idle. This way you can determine if the fuel pump is faulty before you start driving.
3. The engine starts with difficulty or does not start at all. Quite often this happens because the fuel pump has completely failed. The symptom is not the most common, since the reason that the engine does not start may lie in a variety of malfunctions.
4. The car's dynamics deteriorate. When you press the gas pedal all the way to the floor, the car jerks or does not respond at all to moving the pedal. In this case, the fault may lie not in the pedal, but in the fuel pump.

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Do not forget that all the signs listed above are not one hundred percent. Such malfunctions can be caused by failure of various other engine parts. The engine speed may well fluctuate due to a malfunction of the mass air flow sensor or throttle position sensor.

Such malfunctions most often occur due to low quality fuel or uncleaned injectors.

Electrical diagram of UAZ Patriot until 2007

The electrical circuit diagram is shown in Fig. 1

The conductors of the electrical circuit connections are made of stranded copper wire, enclosed in polyvinyl chloride (PVC) insulation with one- or two-color markings in accordance with the electrical circuit. Groups of conductors are combined into electrical bundles. A common cause of electrical wiring failure is the shorting of wires inside the harness due to a short circuit. In this case, it is necessary to “gut” the entire harness to make sure that there are no internal melts or short circuits along its entire length. In the event of a breakdown in the electrical connections between the nodes of the electrical circuit, the connections from a specific actuator to the node control unit should be “ringed” in accordance with the diagram shown. The designation of the circuit elements is shown in Fig. 2

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 pump diagram

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.

Fuel pump diagram

Causes of malfunctioning fuel pump

Fuel pumps are different. It all depends on the specific brand of car and the characteristics of the pump itself.

Knowing the causes of problems in the vehicle’s fuel system is a necessary condition for its successful repair. Problems may arise for the following reasons:

1. Wiring problems: Wires have become dirty, rusted, or melted. As a result, the electric voltage decreases and fuel pumping becomes more difficult.
2. Debris and dust getting into the gas tank. Rust in the tank. As a result, the fuel becomes unclean and causes problems. Poor quality fuel also pollutes the gas tank.
3. Filter dirty. Fuel pressure decreases and the functions of the device are weakened.
4. Driving with an empty tank. This leads to a decrease in pressure and overheating. It dries out and becomes damaged.

To effectively treat a living organism, it is important to know not only the symptoms, but also the causes of the disease. It’s the same with the operation of car systems: you need to find out the causes of problems in the operation of the fuel pump

The gasoline pump is one of the key elements of the automobile fuel complex. It is responsible for transferring fuel under pressure to the injectors (when the car uses a system in which fuel is injected) or to the carburetor. Like other parts of the car, the pump may stop working properly.

The device can be mechanical or electrical. It all depends on its functional characteristics and structure.

How to check functionality

This is easy to do at home. First you need to remove the pump and place it in a vice. Then connect a hose to each branch pipe. One hose must be directed into an empty container, and the other into a container with gasoline. The mechanism must be pumped by hand. If the fuel moves from hose to hose, then you can be happy. This means everything is fine. If this does not happen, then most likely the part needs to be replaced.

Knowledge of the operation of all vehicle systems and experience in troubleshooting them will help save money and provide invaluable assistance in the event of a breakdown far from populated areas.

Diagnostic device

To determine the pressure in the main line, a device is needed. It's easy to do it yourself. You need to take a 10 atmosphere pressure gauge, a fitting and an oxygen hose with an internal diameter of 9 mm. We twist all the elements and tighten them with clamps.

The meter is connected to the ramp. To do this, remove the plastic cap from the end of the tube. Next, use a tire cap to unscrew the nipple.

Bleed off excess gasoline. Before draining the flammable liquid, place a rag to prevent gasoline from getting on the generator. Smoking and using electrified tools near the hood is strictly prohibited.

The free end of the hose is pulled onto the ramp. Secure the clamp. After connecting the battery, turn on the ignition. They take readings. The pressure of the VAZ-2110 fuel pump injector will deflect the pressure gauge needle to 3 atm.

After starting the engine, observe the movement of the needle. On working equipment, the pressure will be maintained within 2.8-3.2 units. If no deviations are found, then the VAZ-2110 fuel pump, injector and regulator are working correctly. It is advisable to remember the characteristics of the equipment.

The pump capacity is about 2 liters per second. If problems arise with the fuel supply, the pump must be replaced. Before checking the pump, make sure that the remaining elements are in good working order. The filter or mesh may be clogged. The fuel filter is changed and the mesh is cleaned.

How to check and replace the fuel pump relay

If the electric fuel pump does not show signs of life when the ignition is turned on, this does not mean that it has burned out. The cause of the breakdown may also be the “relay”. The simplest method of checking the fuel pump relay is by ear - it should click when the ignition is turned on. If you don’t hear a click, then most likely the relay is faulty.

However, everything is not so simple - the breakdown can be “tricky”, for example, the car does not start the first time. The cause of the breakdown may be burnt relay contacts.

In this case, checking the functionality of the pump is very simple:

1. Remove the protective cover that hides the fuse and relay block.
2. Unscrew the fastenings of the block and remove it; it will remain attached to the wires.

3. Pull the relay out of the block and place a jumper between 2 opposite contacts, so we will supply power directly to the fuel pump.

4. If the electric motor of the fuel pump begins to make noise with this connection, it means that most likely the fuel pump itself is working, and the fault lies in the relay. In this case, replace the relay.

Messages 3

1 Topic by Resmus 2011-04-08 05:44:33

• Resmus
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Topic: Pinout of fuel pump chips

Please tell me the pinout and description of the wires according to the colors of the chip on the fuel pump.

2 Reply from Sir YareG 2011-04-08 06:00:13

• Sir YareG
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Re: Pinout of fuel pump chips

There are all the options here! Choose yours!

3 Reply from Resmus 2011-04-08 09:49:18

• Resmus
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Re: Pinout of fuel pump chips

There are all the options here! Choose yours!

When should you check your fuel pump?

It is necessary to check all potentially faulty components one by one, and the fuel pump first.

Problems when starting and running the engine are not always associated with the fuel pump. Sometimes the signs of a fuel pump breakdown are the same as those of a faulty fuel pressure regulator , injectors or jets, spark plugs and high-voltage wiring. Even experienced specialists who know by heart all the signs of a “dying” pump cannot unambiguously determine the type and cause of the breakdown the first time, and it is necessary to check all potentially faulty components one by one. In this case, the fuel pump is usually checked first. In this case, there are two types of malfunction - the fuel pump does not work at all or does not produce the required pressure. In the first case, the malfunction can be recognized by ear, since it should start when the ignition is turned on. In the second case, you need to know how to check the pressure of the fuel pump. Here you need to use a special pressure gauge. We list the main symptoms of a fuel pump malfunction:

• the engine does not start;
• the engine is unstable;
• the engine lacks traction during sharp acceleration;
• The engine lacks traction at low speeds.

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General diagram of electrical equipment of Kalina

On the electrical circuit of the Lada Kalina model, the pinout of connectors is carried out in several stages. According to the factory drawings, the general position of the elements is initially revealed, then each node is deciphered separately.

1. Right front headlight assembly.
2. Sensor indicating the position of the hood lock.
3. Powering the horn.
4. Starter terminal block.
5. Battery power cables.
6. Generator working unit.
7. Voltage supply terminal for the wiper drive.
8. Left head optics contact block.
9. Right door lift chip.
10. Likewise for the glass lift gearbox.
11. Output to driver's door speaker.
12. Driver's door lock drive.
13. Windshield washer reservoir motor.
14. Overboard temperature meter sensor output.
15. Standard ECM connection connector.
16. Same as 12 for the front passenger.
17. Indicator of the remaining brake fluid in the expansion tank of the system.
18. Same as 11 for the front passenger.
19. The front passenger door power window switch, located in the driver's control unit.
20. Driver's door window lift key.
21. Lock button.
22. Power supply for the lift gearbox for the front passenger door.
23. Input of the mounting assembly.
24. Anti-theft control unit.
25. Likewise for signaling.
26. Pinout on the dashboard.
27. Right turn.
28. Glove compartment lighting.
29. Glove box light switch.
30. Stop key switch.
31. Anti-theft ignition switch terminal.
32. Headlight design.
33. Supply current to the steering column lever connector.
34. Left turn signal.
35. Right rear speaker block.
36. Rear right door electric lock drive.
37. Window window heating unit.
38. Reverse blocking.
39. Hazard breaker.
40. Adjusting the stove fan.
41. Auxiliary resistor for the stove.
42. Stove motor.
43. Power supply for rear left speaker.
44. Rear left door lock terminal.
45. Power supply for fuel pump and float.
46. White reverse lamp switch.
47. Stop button.
48. Cigarette lighter power supply.
49. ZX blocking – solenoid power supply.
50. Chips for a tape recorder or speaker system.
51. Illumination of used ventilation and stove.
52. Supplying voltage and signals to the EUR.
53. Interior lighting lamps.
54. Rear right lampshade.
55. Power to the trunk lid lock.
56. Cargo compartment lighting drive.
57. State license plate illumination.
58. Auxiliary stop lamp.
59. Directly heated windshield.
60. Cargo compartment illumination lamp.
61. Left stern light.

The following is the pinout of the first generation Kalina wires for each section individually. This was done due to the increased complexity of the main circuit, where all elements of the on-board circuits are indicated at once. An inexperienced user will not be able to navigate the generalized instructions.

If everything has been checked, but the fuel pump does not work - article numbers

In general, the pump article number for VAZ-2112 engines looks like this: 21102-1139009-XX. Instead of the letters XX there are numbers, for example 02 or 03. They indicate the manufacturer. So, modules from different factories are not interchangeable! The resistance of the FLS resistor is different in them. However, when replacing the FLS sensor, you can borrow it from the “old” module. That's what they usually do.

Until April 2002, article numbers of the type 2112-1139009 were used.

Almost every module available for purchase contains a built-in pressure regulator. There are also exceptions - KSZC-A243, for example. The meaning is as follows:

• All internal combustion engines with a volume of 1.5 liters are equipped with a ramp with an “external” regulator (2112-1160010);
• The 21124 or 21114 motor requires a built-in regulator.

In conjunction with 1.5 liter engines, you can use any module – both with and without a built-in regulator.

Designations of analogues

• 21102-062213.0XX – instead of the letters XX there will be a plant designation (07, 13, etc.);
• KSZC-A233 or A243 – KSZC brand. No pressure regulator .

Master node of the system

The VAZ-2110 fuel pump is equipped with an electric drive. Its body is lowered into the fuel tank. Gasoline is both a pumpable fuel and a coolant. It should be remembered that traveling with an empty tank is fraught with overheating of the VAZ-2110 injector fuel pump.

This electrical device is an independent unit. Accordingly, its operation does not depend on the state of other mechanisms. A necessary condition for rotating the VAZ-2110 fuel pump rotor is maintaining normal voltage on the on-board network.

The voltage comes through the ignition switch. When the key is moved to position 1, the circuit is closed to turn on the drive. The VAZ fuel pump fills the fuel rail. The engine is ready to start.

If symptoms of poor fuel system performance occur, the pump should be checked. We list the signs that make it possible to replace the VAZ-2110 fuel pump:

• the car is malfunctioning;
• accelerates poorly;
• twitches while driving;
• won't start at all
• gasoline does not flow to the ramp.

First of all, a hearing test is performed. After turning the ignition key to position No. 1, there should be a noise under the rear seat. The sound lasts for a couple of seconds. This means that the pump has pumped up the required pressure.

Purpose

Electric fuel pump VAZ 2110

The principle operation of an electric fuel pump is based on pushing fuel under pressure into the engine. Conventional VAZ fuel pumps suck gasoline from the gas tank; a small gap from the pump to the carburetor allows it to operate at low pressure. Electric fuel pumps of the first VAZ cars worked at the same speed. The industry has launched the production of pumps that meet the growing requirements of the automotive industry; now their operation is completely dependent on the speed of the engine.

Note. The vehicle's electronic system controls the operation of the fuel pump. It corresponds to several factors: ambient temperature, what position the throttle is in, and the composition of the exhaust gases.

Electric fuel pumps operate under pressure, resulting in increased noise and rapid heating. For these reasons, they are installed in the gas tank. Gasoline cools and muffles the sound of the running pump.

Features of the injection power system

The tasks of fuel pumps in carburetor and injection engines are somewhat different. If for a carburetor engine it is important to simply supply gasoline to the carburetor, then for an injection system this is not enough. The fuel pump must not only pump fuel from the tank to the ramp, but also create a certain pressure, without which the engine simply will not start.

Access to the fuel pump in injection cars is also complicated by the fact that in cars of recent years of production it is mounted together with a fuel receiver and a coarse filter directly in the gas tank. This complicates the diagnosis, repair and maintenance of the entire fuel module, but simplifies the design of the pump, since the gasoline itself lubricates and cools it. But this is precisely what often leads to unit breakdowns.

How to check the operation of the fuel pump?

First, you should check the fuse. To do this, check the instructions for its location. Next, you should check the voltage at the pump. Before doing this, be sure to check if everything is in order with the battery. The voltage at the fuel pump terminal must be checked using a multimeter or tester. The instruction manual always indicates the required voltage.

Using a tester, check the voltage supply to the fuse. Often this is where the electrical circuit breaks.

If the search does not yield results, then the voltage should be checked on the contacts themselves. All contacts must be in place and connected to ground. A broken contact or its oxidation leads to failure of the fuel pump system. If no broken contacts are detected, but the voltage drops by more than 1 volt, then the problem is in the wiring or oxidation of the contacts. There should be no short circuit in the wiring.

If, after checking the voltage, contacts and fuse, you do not find any problems, then the problem lies in the fuel pump itself. In this case, the fuel pump will most likely require replacement. In practice, it most often turns out that replacement is a last resort. First, you should try to restore and test the fuel pump again.

Before you check the fuel pump, you need to remember that, as mentioned above, pressure is the most important characteristic of the fuel pump, so it is worth measuring its level.

How to check the pressure in the fuel rail?

You will need a pressure gauge that measures pressure in the range from 7 to 10 atmospheres. If you choose a pressure gauge with a large margin, you risk getting less accurate measurement results. Specialized stores sell a kit for measuring pressure, but you can also design your own device.

If you want to assemble the device yourself, you will also need a hose with an internal diameter of 9 millimeters. You will also need plumbing tow, with which you can seal the connection between the pressure gauge and the tube. All parts are connected and tightened using a clamp. You will also need a car spool. Next you need to perform a series of actions:

1. Place the car on a level surface that is prevented from rolling, turn off the ignition and open the hood.
2. Check that the injection nozzles have access to the fuel rail.
3. Find the fuel pressure plug and remove it. Then you should unscrew the nipple using the spool.
4. Prepare an empty container (a regular bucket will do) and a clean rag. This is necessary to collect residual fuel, which under pressure can splash out in different directions. Therefore, take care of the safety of your skin (especially your face and eyes).
5. Connect the device to the fitting and begin checking the mechanism.

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Checking the pressure in the fuel rail should occur in four operating modes of the power unit:

• when the ignition is on;
• at idle engine speed;
• code the fuel pressure regulator tube is reset;
• when the drain tube is compressed.

Fuel rail pressure measurement results

The results may vary slightly for different car models, but in general they should be as follows:

• when the ignition is turned on, the pressure must be at least 3 atmospheres,
• at idle engine speed - at least 2.5 atmospheres,
• when the pressure regulator tube is reset - at least 3.3 atmospheres,
• when squeezing the drain tube - at least 7 atmospheres.

Fuel rail pressure fluctuates slightly during preparation. When you press the pedal, it suddenly takes on a value of 3 atmospheres; when you release the pedal, it drops to 2.5 atmospheres. When fuel enters the fuel system, turn off the ignition and begin observing the pressure gauge. The pressure in this case should drop to 0.7 bar and remain unchanged.

If the pressure drops to zero, there may be a problem with the fuel pressure regulator. In this case, the regulator must be replaced immediately. The cause could also be the fuel pump check valve.

It is necessary to observe the behavior of the pressure gauge even at 3,000 engine speeds. A drop in pressure will indicate a faulty fuel pump. Sometimes the fuel pump cannot reach the required pressure for a long time. In this case, the problem lies in a clogged fuel filter, which needs to be replaced, or in a dirty fuel pump mesh (read more about where the fuel filter is located).

If the above methods do not reveal a malfunction of the fuel pump, you will have to diagnose other units (DPZD, IAC, mass air flow sensor, compression in the engine and some other indicators and parts).

Why is it needed?

There is a coarse filter that comes first from the gas tank. After all, first the lid where the fuel tank is located is opened, a gun is inserted there, the magic button is pressed and the fuel flows. Yes, it takes a lot of your money along the way, but what can you do? The location of the tank can be on the left or right, but this does not play a special role. Coarse cleaning, which is a mesh that traps large particles of debris.

This is followed by a fine filter. This is exactly what we will talk about. This element is called a fuel filter. With its help, small particles are retained. But even they can penetrate your diesel engine or gasoline injector.

Dust, dirt, debris, rust elements. All this can penetrate the system, causing a clogged pipe, tube, valve, fuel hose, or fuel pump components. Nothing good will come of this if timely replacement is not made.

To understand how to replace the filter, which element to choose and how to choose an analogue for the device you are going to change, you need to have at least a basic understanding of such an important component of the car.

I suggest starting with varieties.

Kinds

Modern fuel filters installed on Ford Focus, Nissan Almera, Hyundai Solaris, Nexia, Mazda, Opel, BMW e60, Renault Logan and Megane, Kia Rio and many others have at least two degrees of purification.

• First degree. This is a rough cleansing that allows you to get rid of large contaminants. Not to be confused with a regular mesh in the tank, which is not available everywhere.
• Second degree. Fine cleaning. This is the main task that falls on the shoulders of the filter.

And here you probably have the main question - where is the filter device located? I don't know. No, I can answer, but if you tell me specifically what make of your car or what year of manufacture. After all, on the same Chevrolet Niva, different Opel, Toyota, Mazda models, on the Volkswagen Passat B3, as well as on the domestic VAZ 2114, 2112 and 2110, the location may differ.

However, they are always located somewhere between the engine and the gas tank, since the filter's job is to prevent contaminants from entering the engine while the fuel moves from the tank to the engine. What's in the gas tank itself? That's right, a coarse cleaning device. This is an additional filter element so that any unscrupulous gas stations do not spoil your car.

Now let’s talk about the types of filters themselves. What element will be on the car? It depends on the type of engine. There are three of them, as you know. Except for electric motors. Well, there is no need for a fuel filter, as you understand.

Therefore, there are three types of filters:

• carburetor;
• diesel;
• injection.

Location

So you bought yourself a brand new sedan and you think it’s time to change the filter for this engine. Want to choose the best? Well then, take a closer look at Cummins devices. Mann, Hertz. They have proven themselves well, and they cost quite a bit.

You probably know whether your engine is diesel, injection or carburetor

This is important to understand the location of the fine filter, that is, our today's hero

1. Carburetor. In these engines, the TF (fuel filter) is placed in front of the carburetor itself, and is often in a transparent housing to control contamination. These are the most basic devices, because the carburetor is the least demanding on the quality of fuel.
2. Injector. It uses nozzles and therefore requires high-quality filtration. And the fuel is supplied under high pressure. Therefore, the filters are enclosed in durable metal housings. The TF has to be regularly maintained, cleaned and monitored for its condition. They are placed mainly under the bottom of the car to make it easier to dismantle and replace.
3. Diesel. A diesel engine also needs high-quality purified fuel, since the system is quite sensitive. Diesel fuel has a higher moisture content than gasoline. The TF is designed to filter debris and remove accumulated moisture. A separator is provided for this purpose. The location is quite simple - between the engine and the pump that pumps fuel.

Any fuel system must include a TF. They are replaced assembled, that is, there is no point in removing the filter elements themselves (usually special paper), leaving plastic or metal. Be sure to look at the number and article number of the filter that is installed on your machine, and check the operating manual from the factory. This is the only source of truthful information regarding the maintenance of your particular vehicle in this configuration and with this type of engine.

Possible causes of fuel pump malfunction

Mechanical fuel pump disassembled

A mechanical fuel pump may fail for the following reasons:

1. If the integrity of the diaphragm is damaged.
2. After dirt accumulates under the valves.
3. When the filter is clogged.
4. When the spring loses its elasticity.
5. If the seal of the housing is broken.
6. Due to natural wear and tear of parts during operation.

The electric fuel pump of a modern car is quite reliable. Malfunctions in it arise only due to the influence of certain factors, among which the most common are the following:

Burnt contacts inside the fuel pump

1. Faulty wiring in the form of dirty, rusty, melted or damaged wires in the fuel complex interferes with the operation of the device and also limits the required current parameters, making it difficult to pump fuel.

2. Debris and foreign impurities in the fuel tank in the form of rust, dirt, water, mechanical particles that penetrate the fuel pump and cause its breakdown.

Clogged fuel pump filter

3. A clogged fuel filter with debris from the tank contributes to a sharp decrease in the pressure created by the pump and a deterioration in its operating parameters.

Melted fuel pump turbine

4. Driving a car for a long time with a small amount of fuel, during which the pump is not immersed, experiences significant overheating, quickly consumes internal lubricant and fails.

5. Natural wear of the rubbing parts of the pump.

Problems with the operation of the vacuum type device

The vacuum pump may malfunction. This can happen for several reasons: