Gasoline pump VAZ 2107: purpose, malfunctions and repair

The fuel pump of the classic Zhiguli is one of the weak points of these cars. The mechanism causes a lot of problems for car owners, which is especially evident in hot weather. If there are problems with the fuel pump, you need to know both the causes of their occurrence and how to eliminate them.

Gasoline pump carburetor VAZ 2107

One of the mechanisms of the power supply system of any motor is the fuel pump. The start-up and operation of the power unit directly depends on its performance. Mechanical gasoline pumps of the diaphragm type DAAZ 2101 were installed on the carburetor "sevens". Due to the simple design, the mechanism is maintainable. However, he often causes problems for the owners of the Zhiguli. Therefore, it is worth dwelling on the work and malfunctions of this node in more detail.

The main function

The job of the fuel pump is to supply fuel from the tank to the carburetor.

The VAZ 2107 power supply system with a carburetor engine consists of the following elements: 1 - fuel pump; 2 - hose from the fuel pump to the carburetor; 3 - carburetor; 4 - back tube; 5 - sensor for level indicator and fuel reserve; 6 - safety shield; 7—tank ventilation tube; 8 - fuel tank; 9 - gaskets; 10 — a collar of fastening of a fuel tank; 11 - front tube; 12 - fuel fine filter

The design of the assembly is not perfect, so it is one of the weak points in the car. This is explained by the fact that the impact of constant loads and the poor quality of gasoline lead to natural wear of the elements. This is what causes the device to fail. If a problem occurs with the pump, the engine starts to work intermittently or stops functioning altogether.

The fuel pump has a simple design, but is one of the weak points of the car.

Design and operation

The mechanism is made of several parts interconnected by fasteners. In the upper part of the body there are two fittings through which fuel is supplied and pumped into the carburetor. The design provides a lever that allows you to manually pump gasoline from the tank into the fuel system, which is important after a long parking of the car. The main elements of the node are:

• pusher;
• spring;
• balance;
• cap;
• cover screw;
• nut;
• mesh filter;
• membranes (working and safety);
• bottom and top plates;
• stock;
• valves (inlet and outlet);
• manual pumping lever.
  

  The design of the fuel pump: 1 - discharge pipe; 2 - filter; 3 - body; 4 - suction pipe; 5 - cover; 6 - suction valve; 7 - stock; 8 — manual fuel pumping lever; 9 - spring; 10 - cam; 11 - balancer; 12 — mechanical fuel pumping lever; 13 - bottom cover; 14 - internal spacer; 15 - outer spacer; 16 - discharge valve

The principle of operation of a classic gasoline pump is based on creating the pressure necessary to maintain the required fuel level in the carburetor chamber. Thanks to the diaphragm, the flow of gasoline stops or decreases when the pressure limit value is set in the fuel line. On carburetor "sevens" the fuel pump is located under the hood on the left side of the cylinder block. It is fixed on two studs through a thermal spacer and gaskets, which are also used for adjustment. The spacer is also a guide for the pump rod.

The device works in the following order:

• the pump pusher is driven by a drive cam operating from a gas distribution mechanism;
• the membranes inside the fuel pump move and create pressure and vacuum in turn in the chamber;
• if the pressure drops, the outlet valve closes and fuel enters through the intake valve;
• when the pressure rises, the valve at the pump inlet closes, and gasoline is supplied through the hose to the carburetor.

Under the action of the pusher, which is controlled by the gas distribution mechanism, a vacuum and pressure are alternately created in the fuel pump chamber, due to which the fuel suction strokes and its supply to the carburetor are ensured

Which fuel pump is better

When a fuel pump malfunctions, the question often arises of choosing a new device. Zhiguli owners mainly prefer the products of two manufacturers: DAAZ and Pekar. If there are problems with the factory mechanism, for example, when it overheats, many change it to the second option, explaining that the Pekar pumps do not have a tendency to form a vapor lock, which causes defects in the device in hot weather. In fact, this opinion is erroneous, since they also have such a problem, as evidenced by the numerous reviews of car owners. It should also be taken into account that Pekar costs 1,5–2 more than DAAZ. Therefore, the standard fuel pump is the best choice in terms of reliability, price and quality. The cost of a factory pump is 500–600 rubles.

The Pekar gas pump, along with DAAZ, is considered one of the best for the classic Zhiguli

Table: parameters of fuel pumps from different manufacturers for the "classic"

test data	"Baker"	DAAZ	QH	OTA
Zero feed pressure (at a crankshaft speed of 2 thousand rpm), kgf / cm²	0,26	0,28	0,3	0,36
Productivity per free drain (at a crankshaft speed of 2 thousand rpm), l/h	80	76	92	74
Suction period at speed crankshaft 2 thousand rpm, s	4	13	9	6
Valve tightness at a pressure of 0,3 kgf/cm² (fuel leak within 10 minutes), cm³	8	12	8	8
Place	3	4	1 – 2 Feet	1 – 2 Feet

The QH pumps are made in the UK, while the OTA pumps are made in Italy. However, these devices have some features: the QH pump does not have a lever for manual fuel pumping, and the housing is made non-separable. The Italian mechanism has excellent parameters compared to others, but its price is almost 3 times higher than Russian products.

Symptoms of a malfunction of the gasoline pump

A car enthusiast with experience can determine the malfunctions of his car by his behavior or by extraneous sounds. This also applies to the fuel pump. If knowledge is not enough, it is worth considering the following characteristic signs indicating problems with the fuel pump:

• the motor does not start;
• the engine stalls almost all the time;
• the power and dynamics of the car are reduced.

However, it should be borne in mind that power can also decrease for a number of other reasons: problems with piston rings, valves, etc. If the fuel pump is completely faulty, the engine will not be able to start.

Does not pump the gasoline pump

There may be several reasons why the device does not supply fuel. Before you start troubleshooting, you need to make sure that there is gasoline in the tank. It happens that the level sensor shows incorrectly and the problem comes down simply to the lack of fuel. You also need to make sure that the filter elements are not clogged, but it is better to replace them, because they are inexpensive. After these steps, you can proceed to the diagnosis.

Due to clogged fuel filters, the pump cannot supply the required amount of fuel to the carburetor

Causes of problems can be:

• wear due to long mileage;
• diaphragm damage;
• insufficient spring stiffness as a result of stretching;
• contamination of valves;
• seal failure.

If the gas pump on the "seven" does not supply fuel, then there are two ways out of this situation: install a new device or disassemble the old one, diagnose and replace damaged parts.

On my car, a situation once arose that indicated a lack of fuel for the engine: there was no normal dynamics, the engine periodically stalled and would not start. There was enough gas in the tank, the filters were in good condition, but the car was not moving. After lengthy investigations and clarification of the reasons for this phenomenon, the problem was found: the fuel supply hose from the pump to the carburetor swelled inside, which indicated a poor quality of the product. The internal section has become very small and insufficient to pass the required amount of fuel. After replacing the hose, the problem disappeared. In addition, I change fuel filters at least every 5 thousand km. mileage (preferably more often). I have them before and after the fuel pump. As practice shows, even when two filters are installed, as well as if there is a mesh in the fuel pump itself and at the carburetor inlet, debris still enters the float chamber. This leads to the fact that the carburetor periodically has to be cleaned.

Video: VAZ fuel pump does not pump

The fuel pump does not pump at all! Or the problem is in stock!!!

Stops pumping hot

One of the problems of the classic "Lada" is the overheating of the fuel pump, which leads to a violation of its performance - it simply stops pumping. The problem is due to the formation of a vapor lock, which shuts off the supply of gasoline. There are several ways to solve the problem: pour water on the cooling pump or ride with a wet rag on it. These methods are applicable in a critical situation, but by no means for everyday use. The problem is eliminated by adjusting the fuel pump using gaskets, replacing the rod, replacing the assembly itself, or using better fuel.

Checking the fuel pump

If there are suspicions or characteristic signs of a fuel pump malfunction, the mechanism should be checked. To do this, perform the following steps:

1. Loosen the hose clamp that supplies gasoline to the carburetor, and then pull the hose off the fitting. Gasoline will flow out of the nozzle, so it is better to lower its edge into an empty container.
   

   We loosen the clamp and tighten the hose that supplies fuel to the carburetor
2. We try to manually pump fuel with a lever.
   

   Lever manually trying to pump fuel
3. Gasoline under pressure should flow from the outlet fitting. If the pump pumps, then it can be considered serviceable. Otherwise, we continue the diagnosis.
4. Loosen the clamp and remove the hose from the inlet fitting of the fuel pump.
   

   We loosen the clamp and pull the fuel supply hose from the gas tank
5. We clamp the fitting at the inlet with our finger and try to pump it up. If a vacuum is felt (the finger sucks), then the pump valves are functioning. If this is not the case, the assembly must be repaired or replaced.

Fuel pump drive

The fuel pump VAZ 2107 is powered by a pusher (rod) and an eccentric located on the shaft of auxiliary devices (“pig”, intermediate shaft), which is driven by the timing mechanism through a gear. Auxiliary devices include distributor, oil and fuel pumps.

Operating principle

The drive works as follows:

• the intermediate shaft rotates through the timing chain;
• the eccentric acts on the rod and pushes it;
• the rod presses the fuel pump lever, ensuring its operation.

Fuel pump drive malfunctions

As the fuel supply unit wears out, malfunctions are possible that affect the performance of the latter.

Rod wear

The main sign of the development of the stock - the car does not develop the required speed. If the car accelerates, but, having gained speed to a certain value, it does not develop it anymore, the reason is the wear of the rod. Recently, the pusher is made of such low-quality metal that it leads to the development of literally 500-1000 km. The edge of the stem on the eccentric side simply flattens out, which indicates the need to replace the part.

Rod wear directly affects the performance of the fuel pump

The fuel pump rod should have a length of 82,5 mm.

Fuel pump repair

To replace or repair the pump, it will need to be dismantled from the engine. Of the tools you will need:

• key 13 mm;
• crosshead screwdriver.

Removing the fuel pump

We dismantle the node in the following order:

1. Wipe the pump with a rag.
2. We disconnect both hoses (at the inlet and outlet) by loosening the clamps with a screwdriver.
3. We pull the hoses from the fittings.
   

   After loosening the clamps, we pull both hoses from the fuel pump fittings
4. Using a 13 mm wrench or a head with an extension, unscrew the 2 fastening nuts.
   

   We unscrew the fasteners of the fuel pump with a 13 mm wrench
5. Carefully remove the fuel pump.
   

   Remove the fuel pump from the studs

If the rod needs to be replaced, then simply remove it from the heat-insulating spacer and change it to a new one.

To replace the stem, remove it from the heat-insulating spacer

Once, a situation arose on my car when engine oil was leaking from the place where the fuel pump was installed (in the area of ​​\uXNUMXb\uXNUMXbthe gaskets). The cause was not immediately identified. At first I sinned on the gaskets between the engine block and the spacer, as well as between it and the fuel pump. Replaced them, but did not achieve a positive result. After re-dismantling the mechanism, I examined all the elements more closely and found that the heat-insulating spacer had a crack through which oil leaked. I had to replace it, after which the problem disappeared. In addition to the described case, there was a similar situation when oil was leaking at the location of the fuel pump. This time, the pump itself was the culprit: oil oozed from under the axis of the manual fuel pump lever. There were two ways out of the situation: accept or buy a new product. I bought and installed a new pump (DAAZ), which still works properly and does not leak.

Disassembly

To disassemble the fuel pump, you need to prepare:

• 8 and 10 mm wrench;
• cross screwdriver.

The procedure for disassembly is as follows:

1. Loosen the bolt holding the top cover.
   

   To dismantle the top cover, unscrew the bolt with an 8 mm wrench.
2. We dismantle the cover and remove the filter from the fine mesh.
   

   Remove cover and strainer
3. We unscrew the 6 screws fixing the two parts of the device case.
   

   The parts of the case are interconnected by six screws, unscrew them
4. We separate the body parts.
   

   After unscrewing the fasteners, we separate the two parts of the case
5. We turn the diaphragms by 90 ° and remove them from the housing. Dismantle the spring.
   

   Having turned the diaphragms by 90 °, we take them out of the housing together with the spring
6. Loosen the nut with an 8mm wrench.
   

   To disassemble the diaphragm assembly, it is necessary to unscrew the nut with an 8 mm wrench
7. We disassemble the diaphragm assembly, removing the elements in series.
   

   After unscrewing the fasteners, we disassemble the diaphragm assembly in parts
8. We look at diaphragms. If there are delaminations, tears or the slightest traces of damage on the elements, we change the diaphragms for new ones.
9. We clean the filter, after which we assemble the pump in the reverse order.

During assembly, the strainer must be installed so that its opening is above the valve.

The mesh filter during installation must be positioned with a hole above the valve

Valve replacement

The valves of the VAZ 2107 fuel pump are included in the repair kit. To replace them, you will need a needle file and suitable tips for dismantling.

The fuel pump repair kit contains all the necessary parts for repair

The sequence of actions for disassembly is as follows:

1. We remove the punching with a needle file.
   

   To remove the valves, it is necessary to remove the punches
2. We press out the valves with suitable tips.
   

   We press out the valves with suitable extensions
3. We install new parts and core the saddle in three places.

Installation and adjustment of the fuel pump

The installation of the fuel pump on the "seven" is carried out in the reverse order of removal. The process itself does not cause difficulties. However, attention should be paid to gaskets, since their thickness has a direct impact on the operation of the mechanism.

The adjustment of the position of the assembly must be carried out if, after removing it, the gaskets were replaced or the old seals were strongly pressed in.

The fuel pump is sealed with several gaskets:

• adjusting (thickness 0,7–0,8 mm or 1,1–1,3 mm);
• heat-insulating;
• sealing (0,27–0,33 mm).
  

  The fuel pump is attached to the engine through three gaskets.

Adjusting and sealing gaskets differ only in thickness. There must always be a sealing gasket between the engine block and the heat-insulating element.

The fuel pump is adjusted as follows:

1. Install the sealing gasket.
   

   First, a sealing gasket with a thickness of 0,27–0,33 mm is mounted on the studs
2. We insert the stem into the spacer.
3. We put the spacer on the studs.
   

   After the sealing gasket, install the heat-insulating spacer
4. Install the adjuster.
   

   Between the spacer and the fuel pump we install an adjusting shim 0,7–0,8 mm thick
5. We tightly press the set of gaskets to the block, after which we slowly turn the engine crankshaft by the pulley with a key, choosing the position of the rod in which it protrudes minimally in relation to the surface of the adjusting gasket.
6. With a metal ruler or caliper we determine the outlet of the rod. If the value is less than 0,8 mm, we change the adjusting seal to a thinner one - 0,27–0,33. With values ​​​​of about 0,8–1,3 mm, which is the norm, we do not change anything. For larger values, we install a thicker gasket (1,1–1,3 mm).
   

   We scroll the engine crankshaft so that the fuel pump rod protrudes minimally from the spacer, and measure the value with a caliper

Video: how to adjust the fuel pump on the "classic"

removing the VAZ fuel pump - the principle of adjustment (visual aid) PEKAR

Electric fuel pump for VAZ 2107

Increasingly, the owners of the "classics", including the VAZ 2107, are installing modern devices on their cars. So, a mechanical fuel pump is replaced by an electric one. The main goal of introducing an electric fuel pump is to get rid of the problems that arise with standard pumps. However, you need to understand that if on injection "sevens" such a mechanism is installed directly in the gas tank, then on carburetor cars it is placed under the hood.

Which one can be installed

As an electric fuel pump on the "classic" you can install any device designed to work on injection cars. Based on the feedback from Zhiguli car owners, Chinese-made pumps are often used, as well as Magneti Marelli and Bosch. It is important to know that the product must provide low pressure. A regular mechanical pump produces about 0,05 atm. If the indicator is higher, then the needle valve in the carburetor will simply pass fuel, which will lead to its leakage outward.

VAZ can be equipped with low-pressure electric fuel pumps from different manufacturers

Installation of an electric fuel pump

To introduce an electric fuel pump to the carburetor "seven" you will need a certain list of materials:

• tee 8x6x8 mm;
• fuel line for VAZ 2107;
• check valve from the "eight";
• fitting 8 mm threaded;
• clamps, pads from Kalina for a four-pin relay (3 pcs.) with a fuse holder;
• the four-contact relay itself (3 pcs.);
• fuel jet (150);
• fuel return hose from the "eight";
• wires;
• non-latching button.

We carry out the work in the following sequence:

1. We lay the fuel pipe (return) parallel to the regular fuel line, fixing it in the factory places.
   

   We lay the return pipe parallel to the regular fuel line
2. We cut the fitting 8 mm into the cover of the fuel level sensor.
   

   We cut the fitting 8 mm into the cover of the fuel level sensor to connect the return line
3. We install an electric fuel pump under the hood in a convenient place, for example, on the left mudguard.
   

   We mount the electric fuel pump on the left mudguard in the engine compartment
4. At the carburetor inlet, we install a tee with a 6 mm thread cut inside the tube, after which we screw in the fuel jet by 150: it is necessary to create pressure, otherwise gasoline will go to the tank (to the return line), and not to the carburetor. This will lead to dips when you press the gas.
   

   At the inlet to the carburetor, we install a tee with a jet to create the necessary pressure
5. We install a check valve that prevents gasoline from draining into the tank during long periods of inactivity.
6. The electrical connection of the electric fuel pump is carried out according to the scheme.
   

   We connect the electric fuel pump to the charging lamp, starter and power through three four-pin relays
7. The block with the relay is also located on the mudguard, but can be moved higher.
   

   The block with the relay is also installed on the mudguard
8. We dismantle the mechanical fuel pump and put a plug (metal plate) in its place.
   

   Instead of a mechanical fuel pump, install a plug
9. We mount the swap button in the cabin, for example, on the steering column cover.
   

   We install the fuel pumping button on the steering column cover

Video: installing an electric fuel pump on a VAZ 2107

Upon completion of the installation of the mechanism, it will function according to the following algorithm:

• after turning on the ignition and pressing the pumping button, the pump works and pumps up gasoline;
• when starting the starter, the fuel pump is turned on;
• while the engine is running, the pump is powered by a generator;
• after the engine stops, the operation of the unit stops.

Installation Advantages

Zhiguli owners who have installed an electric fuel pump on their cars note the following advantages:

• an engine with such a device runs more stably at idle;
• with a sharp increase in speed, the car responds well to the pedal, there are no dips, which is not observed with a mechanical pump;
• when switching speeds, smoothness is noted, and with a sharp release of gas, there are no twitches;
• at high speeds, the motor spins better;
• there are no jerks at low speeds when starting the car after a long trip.

The VAZ 2107 gasoline pump sometimes has to be repaired or changed. This is not as difficult to do as it might seem at first. Repair and adjustment work is carried out with a minimum set of tools in accordance with step-by-step instructions.