Lambda probe
Operating principle
The task of the lambda probe T4 conveyor (see Fig. 275) is to periodically supply the microprocessor module with data related to the composition of the exhaust gases. The microprocessor module constantly adapts to new conditions, thus ensuring the best possible performance of the T4 engine .
Rice. 275 Lambda probe Volkswagen T4
The lambda probe consists of a cylindrical body made of a special ceramic material connected to a metal tube that performs protective functions.
The lambda probe is designed so that it can be placed on the exhaust manifold. The ceramic tip must be in contact with the exhaust gases, and the second tip is vented to the atmosphere. The principle of operation of the lambda probe is based on the properties of ceramic material, which conducts oxygen ions at temperatures above 300 ºС.
If the amount of oxygen in contact with the tips of the lambda probe is different, a potential difference is created.
The voltage thus obtained depends on the difference in oxygen concentration on the side of both tips of the lambda probe. Thanks to the ability to measure the oxygen content in the exhaust gases, the lambda probe allows you to control the composition of the air-fuel mixture. Incorrect oxygen concentration causes power surges. This signal is transmitted to the central guiding device, where the signal is processed. The microprocessor module regulates the fuel supply to the injectors so that the composition of the air-fuel mixture returns to normal.
The T4 lambda probe sends recognizable signals at temperatures exceeding 330 ºС, due to which the microprocessor module, which has the appropriate control system, does not activate the control system during start-up, that is, when the engine is not hot.
The work of the T4 injectors . design Conveyor .