Checking the idle speed (Focus Turnier 1)

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

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