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Operation of machines equipped with a catalyst

Gasoline engines VW T4 serially equipped with catalytic converters. The catalyst requires that the engine is running exclusively on unleaded petrol (unleaded).

Control signals fuel injection system receives from the lambda probe, which is in front of the catalyst in the exhaust pipe and the exhaust gas stream is washed. Lambda probe is The electric sensor, which indicates the residual oxygen content in the exhaust gases by voltage fluctuations and allows a conclusion about the composition of the air-fuel mixture. During a second lambda sensor transmits corresponding signals to the control unit of the fuel injection while continuously changing the ratio of the air-fuel mixture. On the one hand it is required as a result of constantly changing operating conditions (idling, the throttle), on the other hand, because of the additional fuel burning in the catalyst, since the exhaust gas contains a sufficient amount even.

In order to, at temperatures from 300 ?� to 800 ?� C in the catalyst could burn out fuel, air-fuel mixture should contain a greater proportion of gasoline than is required for a clean combustion. Consequently, the car with the catalyst consumption is 5% higher.

The catalyst is located on the site of the additional muffler underneath the machine. The catalyst consists of a ceramic honeycomb shaped body coated with platinum or radium. Fragile ceramic body placed in a heat-resistant elastic wire cloth.

Mounted conventional catalyst is a three-way catalyst. This means that due to such a catalyst lambda regulation simultaneous oxidation of carbon monoxide (CO) and hydrocarbons (HC) and reduction of nitrogen oxides _(NO x).

In order to avoid damage to the lambda probe and catalyst, it is imperative to take into account the following guidelines:

- Refuel only unleaded gasoline;
- Start the engine by towing or push unacceptable: unburned fuel can lead to overheating of the catalyst and damage it. It is necessary to use a second battery;
- Avoid frequent repetition of cold starts. Since unburned fuel accumulated in the catalyst, when ignited is combusted explosively and leads to the exit of the catalyst system;
- When a bad start, do not include a starter without the need for long. To find and repair;
- In the absence of ignition in some cylinders, avoid high engine speeds. If there is no ignition in any cylinder (when testing the engine) unburned fuel enters the catalyst;
- Do not park the car over dry leaves or grass. An exhaust system in the region of the catalyst at a high temperature;
- During the filling or topping up engine oil especially ensure that in any case there was no oil filled above the "max" mark on the dipstick. Excess oil, due to incomplete combustion, falls into the catalyst and can destroy it.