Black smoke from the exhaust is a sign that the engine is burning too rich a mixture of fuel and air. A rich mixture is a mixture that contains less air than is necessary for the complete combustion of the fuel.

This means that a larger amount of fuel enters the cylinders than would belong to a certain ratio of air, due to which incomplete combustion occurs. This incomplete combustion results in black smoke from the exhaust, which contains a large amount of soot.

Fuel injection is a method of preparing a mixture of fuel and air for internal combustion engines. The fuel injection principle consists of injecting fuel into the intake pipe, intake channel, chamber, cylinder, or compression space through a small opening, or injector nozzle.

To create the most suitable mixture, the fuel in front of the nozzle is compressed to a higher pressure than the pressure in the space into which it is injected. Due to the higher pressure and the small size of the nozzle, the fuel is atomized during the injection, which makes it possible to accelerate the formation of the …

A spark-ignition engine with direct fuel injection is a type of piston combustion engine that, unlike a spark engine with single-point or multi-point fuel injection or carburetor method of mixture preparation, does not burn only a homogeneous mixture.

Fuel is injected directly into the cylinder during the intake or compression stroke using the injection valves, atomizing and vaporizing it before the spark plug ignites the mixture with a spark.

A stoichiometric mixture is a mixture of fuel and air that contains the exact amount of air required for perfect combustion of the fuel. This perfect ratio of fuel and air in the mixture is called the stoichiometric ratio.

This article will shed some light on what a stoichiometric mixture is and how it affects the engine.

An air-fuel ratio is a dimensionless number that expresses the ratio between the actual amount of air in the mixture and the theoretical amount (stoichiometric amount) of air corresponding to the fuel used. The coefficient, named in English as the Air-Fuel Ratio, is denoted by the Greek letter λ (lambda).

The coefficient defined in this way is mainly used in the field of internal combustion engines because it is a necessary parameter for the preparation of the mixture. The air-fuel ratio thus thoroughly expresses the mixture's richness level. Each fuel needs a different amount of air for its perfect combustion.

A carburetor prepares the mixture for petrol engines that burn liquid fuel and air. This mixture's preparation consists of atomizing the fuel in the air stream.

Almost all spark-ignition engines used a carburetor in the past, but today it is replaced by injection devices.