Carburetor parts on vehicles without converter
1. Emulsion tube of the secondary chamber; 2. Idle speed correction solenoid valve; 3. Thermoelectric actuator of the air damper; 4. Air damper body; 5. Float chamber gasket; 6. Accelerator pump lever; 7. Bracket; 8. Bracket; 9. Diffuser of the secondary chamber; 10. Economizer jet; 11. Idling correction jet; 12. The main air jet of the primary chamber; 13. Small diffuser of the primary chamber; 14. Economizer valve; 15. The main fuel jet of the primary chamber; 16. Body; 17. Viewing window of the float chamber; 18. The main fuel jet of the secondary chamber; 19. Primary chamber idle jet; 20. Needle valve; 21. Float; 22. Axis; 23. Accelerator pump piston; 24. Emulsion tube of the primary chamber; 25. Check valve of the accelerator pump; 26. Accelerator pump valve; 27. Fuel cut-off solenoid valve; 28. Aperture of the secondary chamber; 29. Accelerator pump coil; 30. Gasket; 31. Adjusting screw; 32. Throttle damper; 33. Hull; 34. Adjusting screw; 35. Thrust air damper; 36. Throttle lever; 37. Thrust accelerator pump; 38. Mixture quality screw; 39. Limit sleeve
Vehicles without converter
Carburettors Nikki 21L - two-chamber, with a falling stream and an automatic air damper. The throttle valve of the secondary chamber opens under the action of a pneumatic actuator.
The carburetor body consists of three sections, the middle section is separated from the throttle section by a heat-insulating spacer.
To adjust the idle speed, a screw with a conical end is provided. Fuel cut-off is provided by a solenoid valve.
For additional enrichment of the mixture at full engine load, an econostat jet is provided.
The mixture preparation system in normal engine operation includes the main fuel jet, emulsion tube, air jet and small diffuser.
For additional fuel injection during hard acceleration, an accelerator pump is provided, which is driven by a rod connected to the throttle lever. The regulation of the fuel dose of the accelerator pump, depending on the thermal regime of the engine, is provided by a solenoid valve controlled by a thermal switch.
The idle speed adjustment screw is closed with a restrictive sleeve.
Automatic increase in idle speed with additional load on the engine (e.g. when you turn on the headlights or the air conditioner) provided by a bypass solenoid valve.
The air damper is equipped with a thermoelectric actuator, which is a helical bimetallic spring heated by the flowing current.
Cars with converter
The carburetors of these vehicles are equipped with a low-response solenoid valve to maintain the stoichiometric composition of the combustible mixture, which is controlled by the processor unit (this unit also controls the ignition timing).
The processor unit receives signals from sensors.
The main control signals are the signals from the airflow pressure and crankshaft angle sensors (angle sensor mounted in the ignition distributor).
Additional sensors, based on the signals from which the composition of the mixture is regulated, are:
- coolant temperature sensor;
- throttle switch;
- transmission neutral position sensor;
- clutch release sensor;
- vehicle speed sensor;
- exhaust sensor.
The control unit compares the incoming information and generates signals that control the ignition timing, the fuel mixture stabilization valve, idling, etc., providing optimal conditions for starting and operating the engine in various thermal conditions.
To reduce the toxicity of exhaust gases and maintain traction on a cold engine, an electric heater is installed between the manifold and the carburetor. After the engine warms up, the control unit closes the shut-off valve, which increases efficiency and reduces the toxicity of emissions into the atmosphere.
Some cars are equipped with recirculation systems and additional air intake.