volkswagen Workshop Repair Guides

Volkswagen Workshop Service and Repair Manuals

Engine code AKU > < Engine code AHG
Evaluation: Idling speed smooth running control display
Evaluation: Idling speed smooth running control display
t  The injection system is equipped with an idling speed smooth running control. There may be power differences between the individual cylinders (component tolerances, jet drillings, compressions etc.) which are recognised and equalized via selective injected quantities.
t  Recognition is carried out at idling speed via the signal from the engine speed sender, which delivers four signals per crankshaft revolution to the control unit. If the signals are delivered at the same rhythm then all cylinders work the same. If one cylinder is weaker then the crankshaft takes longer for the next half revolution. Conversely, a more powerful cylinder accelerates the crankshaft so less time is taken.
t  If the control unit recognises a difference, then the relevant cylinder is given more or less fuel, until the engine runs “evenly” again.
t  The measured value block shows the injection quantity deviation between the individual cylinders and No. 3 cylinder. This is necessary to achieve an even engine idling speed.
t  +...mg/stroke: The relevant cylinder is less powerful than No. 3 cylinder and is therefore supplied with more fuel.
t  ...mg/stroke: The relevant cylinder is more powerful than No. 3 cylinder and is therefore supplied with less fuel.
   

Engine code AKU > < Engine code AHG