The pressure disk of the air mass meter fixed on the movable lever, which is installed between the air filter and the throttle valve, deviates depending on the air depression in the engine. The displacement of the pressure disk of the air flow meter is transmitted to the distribution plunger of the fuel dispenser-distributor, thereby determining the amount of fuel supplied. The fuel quantity distributor, depending on the position of the pressure plate of the air flow meter, supplies the required amount of fuel to the engine cylinders through the injectors, ensuring the optimal composition of the fuel-air mixture. The fuel dispenser and air flow meter form a mixture regulator.
Pilot pressure regulator (or the regulator of the composition of the working mixture when the engine warms up) reduces pressure on the control plunger during engine warm-up. Reducing the control pressure at the same air flow leads to an increase in the fuel supply and, consequently, to an enrichment of the combustible mixture.
An additional air supply valve installed in the air duct, made parallel to the throttle valve, brings additional air to the engine during engine start-up and warm-up, which leads to an increase in the engine idle speed.
To facilitate starting a cold engine, an electromagnetic starting nozzle is provided, the opening time of which is regulated depending on the temperature of the coolant by a thermal time switch.
Adjustment Data
Fuel pressure in the system, kg/cm2: 4.5-5.2.
Control pressure on a warm engine, kg/cm2: 2.7-3.1.
Pilot pressure on a cold engine depending on the coolant temperature (see chart page in section «Six-cylinder engine»), kg/cm2: 0.5-2.0.
Residual fuel pressure in the system, kg/cm2, not less than: 1.7.
Idling mode, rpm: 900±50.
Carbon monoxide content (SO) in exhaust gases, %:
- «318»: 1,1;
- «320»: 3,0.
Fine fuel filter
Brand: Purolator.
Type: «320i» before August 1987: GF 140/1; since September 1978 GF 140/1; «318i»: GF 148.
Fuel storage
Brand and type («318i»): Bosch 0438 170 021.
Chamber volume, cm3 («3201»): 20.
Working pressure, kg/cm2:
- «318i»: 1,7-2.4;
- «320i»: 5,0.
Mixture regulator
Brand and type:
- «318i»: Bosch 0438 040 088;
- «320i»: Bosch 0438 040 009.
Injection nozzles
Brands and type:
- «318i»: Bosch 0437 502 006;
- «320i»: Bosch 0437 502 007 EP/ LKE 7.
Injection start pressure, kg/cm2; 3.1;
Fuel cone angle («320i»): 35°.
Electromagnetic starting nozzle
Brand and type:
- «318i» Bosch 0280 170 410;
- «320i»: Bosch 0280 170 405.
Rated voltage, V: 12.
Working pressure, kg/cm2:
- «318i»: 4,5;
- «320i»: OK. 4.5.
Operating voltage, V («320i»): 7-15.
Power consumption, W («320i»): 37.
Fuel cone angle («320i»): 80°.
Thermal time switch
Brand and type: Bosch 0280 130 214.
Rated voltage, V: 12.
Contact opening temperature,°С: +35.
Duration of switching on, s, no more than: 8.
Pilot pressure regulator
Make and type: Bosch 0438 140 005.
Rated voltage, V: 12.
Maximum allowable voltage (briefly), IN 20.
Working voltage. B: 7-15.
Auxiliary air valve
Brand and type:
- «318i»: Bosch 0280 140 134;
- «320i»: Bosch 0280 140 100.
Minimum voltage, V («3201»): 12.
Maximum allowable voltage (briefly), IN («320»): 20.
Operating voltage, V («3181»): 7-15.