Ford Sierra

1982-1993 of release

Repair and operation of the car

Ford Siyerra
+ 1.2. Identification of the car
+ 2. Maintenance
+ 3. General data
- 4. Engines
   - 4.1. Petrol engines
      + 4.1.1. Technical characteristics
      4.1.2. Adjustment of gaps of valves
      + 4.1.3. System of ignition
      - 4.1.4. Fuel system
         - The Ford carburetor with the changeable section of the diffuser
   Removal and installation of the carburetor
   Dismantling, check and assembly of the carburetor
   Adjustment of speed of idling of the engine and contents WITH
   Adjustment of the starting arrangement
   Adjustment of a cable of a butterfly valve
   Removal and installation of a needle shaft
   Diaphragm of the vacuum regulator
         + Weber 32/36 DGAV carburetor
      + 4.1.5. The repair which is not demanding removal of the engine
      4.1.6. Removal and installation of the engine
      4.1.7. Dismantling of the engine
      4.1.8. Identification of the interacting parts
      4.1.9. Assembly of the engine
      4.1.10. Replacement of pistons
      4.1.11. Removal and installation of an intermediate shaft
      4.1.12. System of gas distribution
      4.1.13. Lubrication system
      + 4.1.14. Cooling system
      4.1.15. Suspension bracket of the power unit
      4.1.16. System of production of the fulfilled gases
   + 4.2. Diesel engine
+ 5. Coupling
+ 6. Transmissions
+ 7. Driveshaft and back bridge
+ 8. Steering
+ 9. Suspension brackets
+ 10. Brake system
+ 11. Body
+ 12. Electric equipment

- The Ford carburetor with the changeable section of the diffuser


The Ford carburetor with the closed butterfly valve in a section

1 – lever of a butterfly valve,
2 – mobile gate of the diffuser,
4 – main fuel jet,
5 – additional fuel jet,
6 – float-operated camera,
7 – screw of adjustment of composition of mix,
8 – the screw of an emphasis of a butterfly valve for adjustment of speed of idling

The Ford carburetor with an open butterfly valve in a section

Motorcraft Venturi Variable called also by the carburetor with the changeable section of the diffuser single-chamber, with the float-operated camera and the fuel spray of changeable section operated by vacuum.

The vacuum which is formed in an inlet collector thanks to operation of the engine operates opening of the gate of the diffuser, and also change of section of the fuel jet closed by the calibrated conic needle. This carburetor has the device of enrichment of mix during start of the cold engine which is switched on automatically and operated by the bimetallic spring reacting to changes of temperature. The accelerating pump enriching mix at bystry opening of a butterfly valve is also operated vacuum.

The main system of a dosage of fuel consists of the main and additional jets, and also the calibrated conic needle regulating supply of fuel in the carburetor diffuser. Fuel arrives from carburetor jets under the influence of the vacuum which is formed in the diffuser through which there passes air (between the main jet and the mobile gate, see rice. The Ford carburetor with the closed butterfly valve in a section and rice. The Ford carburetor with an open butterfly valve in a section).

At small load of the engine the needle connected to the mobile gate almost completely closes the main fuel jet. In process of increase of load of the engine vacuum amplifies and the mobile gate gradually opens diffuser section. Together with it the needle moves, increasing fuel stream section, and also the additional fuel jet opens. The needle is made with a big accuracy and makes an important element of an exact dosage of fuel depending on load of the engine. It is not necessary to regulate (to change installation) needles.

In no-load time when to the engine a small amount of air arrives, the mobile gate is in an extreme, closed position and is kept by a returnable spring of a diaphragm of the vacuum regulator. In process of opening of a diaphragm intensity of the proceeding stream of air grows and vacuum in the diffuser increases. This vacuum, influencing the regulator, causes movement of the gate of the regulator, and together with it the mobile gate and a needle. The provision of a diaphragm in each timepoint is defined by balance of forces influencing it: vacuum and returnable spring.