Freezing of the carburetor

When the air temperature of +9 ° C to -5 ° C, under conditions of high humidity (fog, rain, sleet) in carbs a tendency to freeze. With this weather the likelihood of ice formation on dosing elements increases during long rides on the highway at a constant rate. Ice forms in places where air velocity is very high - at the edge of the throttle and spray. Ice accretion occurs while driving, when the throttle for a long time in one position. Ice blocks the air holes in the transitional system of the first chamber, near the edge of the throttle. Forming a spray, ice reduces their internal section. This leads to a significant enrichment of the working mixture, as the freezing air just the dosage, and quantity of gasoline remains the same. As a result of enrichment spark plugs are covered by a thick layer of soot. Sparks in the candlelight deteriorates so that the engine loses power and eventually stops. Once the car stopped, the ice begins to melt in the carburetor with heat engine. After 5-10 minutes, the carburetor again ready for operation. A typical scheme of heating the air A - Vacuum valve control device; B - valve; C - temperature controller; D - supply of hot air; E - supply of cold air. After starting the engine will be black smoke from the silencer, because the spark plugs still covered with soot, and can not form a strong spark. But after a 10-15 minute drive electrode plugs cleaned of soot and combustion in the cylinders to normal. During long-distance trips in wet and freezing cold weather carburetor can occur every 70-100 km. way. To make sure that the cause of the emergency stop of the car was freezing the carburetor, you must stop immediately after the air cleaner to remove the cover. Type of ice-covered carburetor spray on a hot engine immediately clarify the situation. After stopping the engine carburetor ice is melting quickly, and if you linger with the cover removed the air cleaner, you will only see the dew on the shallow water throttle. Be aware that the freezing of the carburetor is at high humidity and air temperature close to zero. Added to this is that the bits and pieces obzamerzaniyu main metering systems contribute to gasoline with a low boiling point. Noted that when a hard frost does not freeze in the carburetor, as the frosty air humidity is much lower. When driving in the city cycle carburetor freezing is unlikely, because the frequent movement of the throttle contribute sletaniyu thin crust of ice and air speed at the same time is constantly changing. To reduce the chance of freezing the carburetor vehicle manufacturers provide different design heating air at the inlet of the carburetor. In addition, the carburetor heating system are of the throttle with the supply of cooling fluid or electric heaters. Vacuum from the intake manifold is supplied through a rubber tube to a temperature control for the air filter housing. The temperature control is another tube connected to a vacuum device that controls the valve in the nozzle, the air filter. Some other systems use a thermostat, which is directly connected to the valve. In both systems, door opens, closes or is in an intermediate position in accordance with the air temperature. On most systems, with carburetors "Pirburg" warm air from the exhaust manifold is supplied to the entrance of the carburetor air temperature under the hood below 15 ° C. When the temperature rises above 15 ° C temperature control gradually changes the value of vacuum in the system and the damper begins to shut off the warm air. The flap completely override the flow of heated air at a temperature of about 25-30 ° C. Some other systems may shut heating at higher temperatures, in accordance with the instructions of a car manufacturing plant.