Woran erkennt man das Motor zu mager läuft?

What do you realize that a motor is running lean?

For vehicles with petrol engine and G-cat, you can see it at the AU. In this, it is tested whether the mixture fits, it must not be too lean or too fat. Pay attention to the lambda value, 1,000 is exactly fitting, among which is fat, is leaner, the limit values are usually at 0.97 and 1.03, with newer exhaust gas standards also at 0.98 and 1.02.

With oldtimers with carburetor, you can look at the spark plugs. If these are not rough, but light white, the motor is too lean. From a certain point you have a magic jerk anyway, so you can notice it quickly.

In diesel engines there is no “too lean” because diesel engines use the principle of quality control. In this case, the maximum air mass is always sucked in, the load, and the speed control is effected purely by a variation of the fuel quantity. The more load and speed, the more fat the mixture becomes, in idle it is extremely lean, up to Lambda 6, if I remember correctly. Therefore, the demand for petrol or diesel does not make any sense at all.