Schemes of the engine power supply system are shown in fig. 1, 2, 3.

The reliability and durability of the engine, as well as the dynamic performance and economy of the car as a whole, largely depend on the state of the power system.

Scheme of the power supply system for cars of the UAZ-31512 family

Fig. 1. Scheme of the power supply system for cars of the UAZ-31512 family

The power system consists of two fuel tanks, fuel lines, a switching valve, a fuel pump, a sediment filter, a fine fuel filter, a carburetor with a throttle and air damper drive, and an air filter.

In modifications with a preheater, an electric fuel pump is included in the power supply system in parallel with the mechanically driven fuel pump.

The fuel, under the action of the vacuum created by the fuel pump, passes through the fuel intake grid, then enters the sediment filter housing through the fuel line and the switching valve.

Water and large mechanical particles remain in the housing, and the fuel passes through the filter element, which consists of a set of thin steel plates, and is fed through the fuel line to the fuel pump.

After the pump, the fuel passes through the fine filter element and enters the carburetor.

The air necessary for the formation of the working mixture is supplied to the carburetor through the air filter.

Scheme of the power supply system for cars of the UAZ-3741 family

Fig. 2. Scheme of the power supply system for cars of the UAZ-3741 family

Fuel tanks are rectangular steel tanks located on both sides of the vehicle frame.

The tanks are attached to the frame spars from the outside using brackets and clamps.

There are cardboard spacers between the clamps and the tank. The tanks are connected by fuel lines to a switch valve installed under the driver's seat. With it, you can switch the fuel intake from one tank to another.

The capacity of one tank is 39 liters.

At the top of each tank there is a fuel pickup, consisting of a tube and a brass mesh filter, as well as an electric fuel gauge sensor.

In some modifications, a drain hole with a threaded plug is located at the bottom of the tank.

The plastic filler cap has inlet and outlet valves to prevent underpressure and overpressure inside the tank.

On some vehicles, the fuel filler neck is equipped with a retractable pipe for easy refueling.

From the outside, the fuel filler hatch is closed with a cap.

The fuel lines are made of rubber hoses and a copper tube.

The hoses are connected to the fuel pump, the fuel tank switching valve, the sediment filter through fittings with union nuts.

On the branch pipes of the fuel intakes, the carburetor and the fuel fine filter, the hoses are fixed with clamps.

A copper tube is connected at one end through a fitting to a sediment filter, and at the other end is inserted into a rubber hose and tightened with a clamp.

Scheme of the power supply system of a UAZ car with one fuel tank

Fig. 3. Scheme of the power supply system of a UAZ car with one fuel tank

Fuel sediment filter is installed on the left side member of the frame in front of the fuel tank and is designed to separate water and mechanical impurities larger than 0.05 mm from the fuel.

To clean the fuel from mechanical impurities, the filter is equipped with a filter element consisting of a set of thin metal plates.

To remove sediment from the bottom of the filter housing there is a drain hole with a screw plug.

Fuel pump - diaphragm, driven by an eccentric on the engine camshaft.

It is possible to install a pump of one of three models: B9V (451-1106010-40), 900-1106010 and 2105-1106010-50.

The fuel pump consists of a housing, a valve block cover and a drive lever. The valve block is installed in the pump cover.

A filter made of fine brass mesh is located above the suction valves.

To fill the carburetor with fuel when the engine is not running, the pump has a manual drive lever.

To control the tightness of the diaphragm and prevent fuel from entering the crankcase, the pump housing has a drain hole.

The fuel fine filter can be used in two types: collapsible, with a replaceable filter element and non-collapsible.

The dismountable fuel filter is attached to the cylinder head bracket.

It consists of a housing, a rubber gasket, a sealing rubber bushing, a ceramic or paper filter element, a spring, a plastic sump cup and sump cup attachment parts.

A filter with a plastic non-separable housing and a paper filter element is installed on a hose that supplies fuel to the carburetor.

Air filter - dry type, with a replaceable filter element made of non-woven synthetic material, mounted on the cylinder head bracket.

The filter is equipped with an air intake corrugated hose connected to a metal pipe located on the radiator casing bracket on the right.

At an ambient temperature below 5 ° C, to supply heated air to the carburetor, disconnect the corrugated hose from the filter pipe, and turn the damper on the exhaust manifold to the "winter" position.

UAZ power system

For what, with the “10” key, we loosen the nut that fixes the damper (Fig. 4).

The air filter cover has two fittings for connecting hoses of the crankcase ventilation system.

UAZ power system

If the cylinder head cover, due to a misconfiguration, has two pipes for removing crankcase gases, then to prevent unfiltered air from entering the intake pipe, it is necessary to plug the unused small pipe of the air filter cover in any way possible (for example, squeeze with pliers).

The throttle control drive consists of a pedal, a system of rods and levers, tips of adjusting nuts, couplings and a spring.

In addition, the cars have manual throttle control.

It consists of a handle on the instrument panel, a sheathed rod, a bracket and a lever.

The carburetor choke is controlled by a knob located also on the instrument panel.

It is connected to the damper lever by a sheathed rod.

When the knob is in the home position (retracted), the air damper is fully open.

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Carburetor K-151V (Fig. 1) - vertical, emulsion, two-chamber, with a falling mixture flow and sequential opening of the throttle valves

To remove the clutch discs, perform operations 1 to 5 of the section " Replacing the release bearing of the UAZ-3151 "