The device of the engine power system of cars VAZ-2106 and VAZ-2103

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The power supply system includes devices for supplying fuel and air to the carburetor, preparing a combustible mixture and exhaust gases. The power system consists of a fuel tank, fuel pump, air filter, carburetor, intake pipe, exhaust manifold, mufflers and pipelines. Fuel is cleaned on a car by fuel filters installed on the receiving tube of the fuel level sensor in the tank, in the fuel pump and carburetor.

Fuel tank

Fuel tank 39 steel, welded from two halves. The steel sheets are lead-coated on the inside. Outside the tank is painted with black enamel. The capacity of the fuel tank is 39 liters, including a reserve of 4-6.5 liters.

The tank is installed in the luggage compartment of the body on the right along the course of the car on a rubber gasket and is fixed to the body with two clamps tightened with a bolt. The filler neck of the tank is brought into a niche in the right rear wing and is closed with a blind plug 26 on the thread. To access the plug, you must press the front end of the cover on the wing, which closes the niche.

For ventilation and access to atmospheric air, the fuel tank has a hose 28, which is brought out by the second end into the niche of the filler neck. Fuel trapped in the vent hose loop while driving on rough roads forms a fluid lock that prevents the gasoline from evaporating from the tank.

A fuel level sensor 38 is mounted on top of the tank, complete with a branch pipe and a receiving tube 29, equipped with a fuel strainer. The tank has a drain plug, for access to which there is a hole in the floor of the body, closed with a plug. Since 1985, drain plugs on fuel tanks have not been installed on cars.

Fuel lines

Fuel lines 1 and 2 are made of galvanized or lead-coated steel tubes. The fuel lines are interconnected, with the tank, with the fuel pump, as well as the fuel pump 3 with the carburetor 5, with rubber hoses in a fabric sheath and secured with clamps with a screw and a nut. The fuel lines are secured to the body with plastic holders. The openings in the body for the passage of fuel lines are sealed with rubber plugs.

Fuel pump

Fuel pump - diaphragm type, mechanically driven; mounted on the left side of the cylinder block, fixed on two studs through a heat-insulating spacer 33 and shims 34 and 35. Equipped with a lever 22 for manual fuel pumping. Pump flow not less than 60 l/h at a frequency of 2000 cycles per minute. The pressure developed by the pump is 20-30 kPa.

The fuel pump is driven from the eccentric 31 of the oil pump drive shaft and the ignition distributor through the pusher 32. The pump consists of a lower housing 24 with drive levers, an upper housing 9 with valves and pipes, a diaphragm assembly and a cover 12.

The diaphragm assembly has three diaphragms: two upper 18 - working for supplying fuel, one lower 20 - safety, working in contact with crankcase oil and preventing fuel from entering the engine crankcase if the working diaphragms are damaged. Between the working and safety diaphragms, remote outer 19 and inner 17 gaskets are installed. The outer gasket has a hole for fuel to escape to the outside in case of damage to the working diaphragms.

Diaphragms with plates and with an internal spacer 17 are mounted on the stem 21 and fixed on top with a nut. The diaphragm assembly is installed between the upper and lower pump casings. A compressed spring is installed on the rod under the diaphragm assembly. The rod 21 is inserted into the slot of the balancer 25 with a T-shaped shank. This design allows, without disassembling the diaphragm assembly, to remove it from the engine.


In the lower housing 24, on the axis 6, a lever 36 of mechanical fuel supply and a balancer 25 are installed. In the lower housing, also on the axle with a cam 37, a lever 22 of manual fuel pumping is installed, which returns to its original position under the action of a spring 23.

In the upper casing 9 of the pump, textolite hexagonal suction 15 and discharge 8 valves are installed. The valves are pressed by springs to brass seats 7 and 14. A cover 12 is attached to the body with a central bolt from above. A plastic strainer 10 is installed between the cover and the body.

When the engine is running, the eccentric 31 of the drive shaft through the pusher 32 acts on the lever 36 and turns the balancer 25, which pulls the pump diaphragms down by the rod 21. At the same time, the diaphragm spring is even more compressed, a vacuum is created, as a result of which fuel fills the working cavity through the suction valve (cavity above diaphragm). When the eccentric runs off the pusher, the lever 36, the balancer 25 and the rod with diaphragms are released. The diaphragms, under the action of a compressed spring, create fuel pressure in the working cavity, the suction valve 15 closes, and fuel is supplied through the discharge valve 8 to the carburetor float chamber.

With a small fuel consumption, the stroke of the diaphragms will be incomplete; in this case, the stroke of the lever 36 will be partially idle.

When manually pumping fuel, the lever 22 is pressed, the cam 37 acts on the balancer 25 and pulls the rod with the diaphragms. Fuel is sucked into the working cavity. When released, the lever and cam return to their original position under the action of spring 23, and the diaphragms pump fuel into the carburetor float chamber.

When installing the fuel pump on the engine, shims 34 and 35 are selected so that the minimum protrusion of the pusher 32 above the mating plane of the heat-insulating spacer 33 (taking into account the gasket between the spacer and the fuel pump) was 0.8-1.3 mm. The minimum protrusion of the pusher is set by slowly turning the engine crankshaft. Gaskets are manufactured in three types and have a thickness of 0.30; 0.75 and 1.25 mm. Between the heat-insulating spacer and the cylinder block, a gasket 0.30 mm thick must always be placed.