Gasoline pump in VAZ 2108/2109 (carburetor): fault diagnosis, repair and replacement

Repair / From Ekaterina Larina

  • Several ways to check functionality
    Method No. 1
  • Method number 2
  • Method number 3
  • What are the signs of a fuel pump malfunction and the possibility of repairing it?
      For what reasons can fuel pumps fail?
  • What to do if it leaks
  • What to do if fuel does not pump: repair
  • Video instruction: how to repair a fuel pump yourself
  • Replacing the fuel pump on a VAZ 2108/2109
      Preparing tools
  • Step-by-step instructions on how to remove a faulty fuel pump
  • Step-by-step instructions on how to install a new fuel pump
  • Video instruction: how to replace the fuel pump yourself
  • Electric fuel pumps are installed on VAZ 2108 and VAZ 2109 models. The task of this device is to supply fuel under certain pressure into the fuel rail, and from there the injection system distributes fuel into the engine cylinders. In other words, it ensures the transfer of gasoline from the tank to the engine unit. However, electrical devices can cause some problems for owners of VAZ 2108/2109 with a carburetor. Their performance is not always flawless. Owners of domestic cars need to be prepared to know and be able to carry out inspections, repairs and replacements with their own hands.

    What fuel pumps are installed on the VAZ 2108/2109 (carburetor)

    Initially, both carburetor and injection models of VAZ 2108/2109 cars are equipped with DAAZ brand fuel pumps. Their direct manufacturer is the AvtoVAZ plant itself. These devices are characterized by low cost and accessibility for a wide range of car owners: DAAZ can be bought at any auto store.

    However, despite the prices of the domestic manufacturer (from 700 rubles per product), many car enthusiasts prefer to remove the factory one as quickly as possible and install another one. This desire is explained by the presence of a large number of negative reviews from owners regarding the quality of DAAZ.

    I drove around a dozen before buying this! stores... I checked with friends... I scoured the Internet... in general, there is only DAAZ on sale as in the photo... they all leak along the pedal axis... I'm waiting for this one to leak...


    The most budget-friendly type of equipment for fuel systems of domestic cars.
    An alternative equipment option is a petrol pump from Pekar. It is more resistant to all types of influences, and is also characterized by durability. Pekar is a leading manufacturer of automotive components in Russia.

    I've been driving for over 30 years. and I had a lot of fuel pumps and changed them often. Either the membrane will wear out, or the valves will fail. In 2004 I bought myself a new Pekar fuel pump and now I don’t know any grief. With old gas pumps I carried a rag with water in the hot weather. When the gas pump stopped pumping, I soaked a rag and laid it on top, but this gas pump can withstand any temperature. And during this time I only changed the valves, and the membrane is still working. The stem was also changed once. Very good fuel pump I recommend to everyone


    High-quality and durable devices have gained popularity among many Russian VAZ drivers.
    At the owner's request, during repairs, a fuel pump manufactured by the German company Bosch can be installed on the VAZ 2108/2109. The cost of the original device is more than 2 thousand rubles, but the quality will completely cover all costs.

    Fuel pumps in VAZ 2108/2109 cars with injection engines are not located under the hood. Therefore, the search for breakdowns and malfunctions should not begin with the traditional opening of the hood. The device is located directly in the gas tank. That is, getting to it in the event of a breakdown will be quite difficult - you will have to recline or dismantle the rear seat.

    Several ways to check functionality

    Experienced owners of VAZ 2108/2109 cars know exactly how to check the functionality of the fuel pump. Malfunctions related to incorrect fuel supply may not always relate specifically to the pumping device. Therefore, you will need to be able to identify problems with the device yourself.

    Method No. 1

    You will need to turn on the ignition and listen to whether the pump is working or not. A buzzing sound should be heard in the cabin behind one of the rear seats. If there is no characteristic sound of the pump operating, then you will need to check whether power is being supplied to it.

    The block with the relay is dismantled. For the convenience of the driver, the assignments of all relays in the block have schematic assignments. If the relay and fuse are working, then it is recommended to recline or remove the rear seat, open the hatch and measure the voltage on the device itself. Typically, a multimeter or wiring with a low-power lamp is used for this.

    Method number 2

    You will need to replace the fuel pump with a new one. If the problems disappear immediately, it means that the fuel pump was indeed faulty. If the car still cannot be started due to low pressure in the fuel rail, the problem is not in the fuel pump, but in the fuel system itself. It is best to contact specialists.

    Method number 3

    The performance of a gas pump can be checked by measuring the amount of gasoline it pumps over a certain period of time.

    You will need to organize access to the fuel rail and unscrew the spool on the tube. Connect a hose to the hole, the other end of which is lowered into a container for measurement (for example, a three-liter jar). The pump on the “eight” and “nine” pumps approximately one liter of fuel per minute. If the readings are much lower, it means the high pressure filter is clogged.

    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.

    If the pusher is damaged, you need to unfasten the pump, and leave the heat-insulating insert, gasket and the pusher itself on the engine. Rotate the crankshaft to extend the pusher as much as possible.

    We measure the size of the protrusion above the topmost gasket (acceptable value is 0.8 - 1.3 mm). If this value does not correspond, you can try to adjust the gap using thinner or thicker shims. If that doesn't work, change the pusher.

    If the VAZ 2109 carburetor fuel pump does not work correctly, then this affects such an important process as the supply of fuel to the carburetor. Failures lead to a lack of fuel in this part of the car.

    Now we will talk about such a procedure as replacing a VAZ 2109 fuel pump. But, before starting the process itself, let’s do primary diagnostics. To find out the reasons, perform the following steps:

    • First, remove the hose from the discharge pipe. Using the pumping lever, you need to check the fuel supply. If gasoline does not enter the carburetor, the hose is removed from the suction pipe. Now you can find out if there is a vacuum. If it is not there, the fuel pump should be disassembled to check all parts.

    What are the signs of a fuel pump malfunction and the possibility of repairing it?

    The first sign of a malfunction may be a lack of pressure in the fuel supply system. This is expressed by interruptions in the operation of the engine unit (it begins to “cough”), after which the car stalls. Such symptoms can occur both while driving and when the engine is idling.

    However, even earlier, before the fuel pump fails, an attentive driver can diagnose problems. These include:

    • high tone of the engine;
    • having problems starting the engine;
    • gradual loss of power while driving.

    Thus, if you listen to the nature of the sounds while driving and monitor the dynamic performance of the car, you can timely repair or replace the fuel pump without waiting for it to break down.

    For what reasons can fuel pumps fail?

    It is important not only to know exactly how to determine wear and tear of a fuel pump, but also to take into account the reasons why the device may fail.

    The most common causes of breakdowns and incorrect operation of fuel pumps on VAZ 2108/2109 vehicles are:

    • debris in the fuel tank;
    • short circuit in the fuel system wiring;
    • clogging in the fuel filter;
    • pump overheating.

    What to do if it leaks

    Either fuel or lubricant (oil) may be leaking. If liquid leaks are found on the fuel pump body in a VAZ 2108/2109 car, it is recommended to take the following actions:

    • tighten the clamps on the hoses of the device (at the “input” and “output”);
    • check the integrity of hoses and connections;
    • tighten the fuel pump cover bolt (or replace it if the thread has been stripped);
    • replace the pump fitting.

    What to do if fuel does not pump: repair

    In cases where the device does not supply gasoline to the engine unit, you will need to establish the functionality of the gas pump itself. It is quite possible that it is functioning, but some element has failed.

    Repairing a fuel pump is advisable only in cases where it is necessary to replace the smallest part of it. It is worth initially calculating the cost of materials, as well as taking into account the loss of time. It is quite possible that it is easier and cheaper to buy a new fuel pump.

    Repair work to restore the functionality of the fuel pump, if it does not pump fuel from the tank, is carried out taking into account the following details:

    1. The fuel pump will need to be removed from the tank.
    2. Using the tool carefully, you will need to disassemble the device body.
    3. Inspect the pump components and find any damage.

    Next proceed based on the existing problem:

    • if one of the four springs bursts, you will need to replace it (as a rule, springs are inexpensive and are sold in almost all car stores);
    • if the valve plate is seriously worn, this element will also need to be replaced, and the valve seat will need to be hammered into place with a blunt screwdriver;
    • the pump drive rod has started to jam - you can straighten the surface of the rod to make it smoother;
    • the surface of the fuel pump is dirty - you will need to clean the device with a soft, lint-free cloth

    After troubleshooting, you should reinstall the fuel pump and check its functionality by starting the engine. If the ignition problems persist, most likely the problem lies in the fuel system itself, or your device will need to be replaced.

    Video instruction: how to repair a fuel pump yourself

    Correct procedure for disassembly and replacement

    To remove the fuel pump, you need to perform the following sequence of actions:

    • Buy a repair kit right away, its price is cheap
    • Remove the air filter and its housing
    • Disconnect the fuel supply and return hoses from the pump fittings
    • Unscrew the nuts that secure it
    • We remove it carefully, as there is a possibility of damaging the gaskets.
    • Then you should inspect all the parts for cracks, check the tightness of all its valves
    • Make sure that the discharge and suction fittings do not rotate in their sockets
    • Diaphragms should not have peeling or ruptures
    • The filter must be undamaged and absolutely clean
    • Wash all its parts with gasoline and then blow them out with a compressor
    • After checking, replace all damaged parts; it is recommended to change the pump gasket as well.
    • When installing the gasket, apply lubricant like Litol-24 to its surface
    • If the housing is damaged or the main parts are irreparably damaged, replace the pump completely
    • Then you can proceed to installing it back
    • In this case, immediately adjust the feed using shims
    • And for this we measure the protrusion of the pusher
    • Since with a strong protrusion, increased gasoline pressure will be pumped, which will easily break the carburetor shut-off valve
    • In the case when the distance is lower than necessary, when the load increases and the vehicle speed increases, an insufficient amount of gasoline will flow into the carburetor
    • The procedure for installing the pump is the reverse of removal.
    • Also make sure that the arrow located on the body points towards the carburetor
    • When installing the diaphragm unit, it is important to place the holes in its gasket away from the muffler pipe

    Here we have outlined more detailed instructions for removing and disassembling the fuel pump to make it easier for you to do it yourself if a fuel pump malfunction occurs on your VAZ 21093. We conclude here, there should be no difficulties; in addition, you can, of course, watch a video lesson on this topic.

    Replacing the fuel pump on a VAZ 2108/2109

    The procedure for replacing a faulty fuel pump on a VAZ “eight” and “nine” is relatively simple. The main thing is to be careful so that when installing and dismantling you do not accidentally catch parts of other elements of the car.

    Preparing tools

    In order for the work to be completed quickly and not have to be distracted by searching for this or that tool, it is necessary to prepare everything in advance. So, to remove a faulty fuel pump and install a new one, you will need the following set of tools:

    • Phillips screwdriver;
    • flat screwdriver;
    • socket wrench (or head) size 7 mm;
    • extension;
    • open-end wrench 17.

    It is recommended to carry out all stages of operations with gloves so as not to stain or injure the skin on your hands.

    Step-by-step instructions on how to remove a faulty fuel pump

    The first stage of work is to dismantle the old device, which can be divided into several steps:

    1. Turn off the ignition.

    2. Fold down the rear seat in the cabin.

    3. There is a small hatch under the foot carpet in the cabin; it must be opened by removing the fastening screws with a Phillips screwdriver.

    4. Raise the hatch cover.

    5. A plug will appear in your field of view; you will need to bend the latches on it and disconnect its parts.

    6. Next, you need to unscrew the fuel pipes with a 17 wrench.

    7. The tubes must be diverted in different directions so that they do not interfere with further work.

    8. There is a pressure plate under the hatch - you will need to unscrew all the nuts on it to open it.

    9. The fuel pump is located under the plate; to get it out you will need to pry off the rubber seal with a screwdriver.

    10. As soon as you manage to lift the device a little, you will need to tilt it so as not to touch the body of the fuel level sensor.

    Step-by-step instructions on how to install a new fuel pump

    Further actions involve the reverse order:

    1. Carefully insert the new device into the hole, not forgetting to change the O-ring.
    2. Retighten all nuts on the pressure plate.
    3. Connect the fuel pipes to each other.
    4. Connect the two parts of the plug.
    5. Close the cavity with the hatch cover and screw the hatch.
    6. Place the carpet in its original place.

    Video instruction: how to replace the fuel pump yourself

    Thus, you can diagnose and repair the fuel pump in VAZ 2108/2109 cars yourself, without involving service station specialists. The procedure for determining the performance and replacing a faulty device is quite simple, so performing these procedures yourself will not cause difficulties even for inexperienced drivers.

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    Repair of carburetors VAZ 2108–2109

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