Skoda OCTAVIA 2004 Workshop Manual page 62

01
engine idling (engine
models
ä
♦ The fuel injection system features a smooth idling control. It is able to detect differences in performance between the
individual cylinders (parts tolerances, injector flow, compression, etc.) and to compensate for these by selective
metering of the quantity of fuel injected in the idling speed range.
♦ Such differences are detected in the idling speed range on the basis of the signal supplied by the engine speed
sender, which supplies four signals for each crankshaft revolution to the control unit. If the signals are received in the
same rhythm, all the cylinders are performing the same work. If one cylinder has a weaker performance, the crank-
shaft requires a longer time for the next half crankshaft revolution. In contrast, a cylinder with a stronger perform-
ance accelerates the crankshaft to such an extent that it requires a shorter time.
♦ If the control unit has detected a variation, the cylinder in question is immediately supplied with a greater or lesser
injected quantity until the engine is again running smoothly.
The relevant cylinder has a weaker performance than cylinder and is therefore supplied with more fuel.
♦
♦ - ... The relevant cylinder is stronger in performance than cylinder
measured value
Idling controller - injected quantity cylinder
♦
♦
♦
------------ ------------
Self-diagnosis
Idling controller - injected quantity cylinder
♦
♦
♦
Idling controller - injected quantity cylinder
♦
cylinder
♦
cylinder
♦
o.k.
cylinder weak
cylinder strong
not less
in display
K
Idling controller - injected quantity cylinder
♦
cylinder
♦
cylinder
♦
o.k.
cylinder weak
cylinder strong
o.k.
weak
strong
°C)
and is therefore supplied with less fuel.
o.k.
weak
strong
OCTAVIA
Edition 12.00
S00.5111.54.20