Checking the idle speed

The idle speed is constantly adjusted by the control unit via the idle speed servomotor, depending on the consumer switched on (e.g. headlights, air conditioning or servo control). Focus gasoline engines idle at approximately 900 rpm, Endura diesel engines crank at approximately 850 rpm.

For preventive control, you need an accurate tachometer. In workshops, an engine tester is always used for this. If the speed does not correspond to the factory data, then it is not adjusted in isolation: the experts look for a malfunction in the entire engine management system. If the battery was disconnected, then modern on-board computers take several kilometers to acquire the old form. These learning phases can also be accompanied by increased idle fluctuations.