Idle speed parameters.
Idle Speed - Sets the hot idle speed.
Disable idle valve - Disables the idle valve error checking if no idle valve is present.
Idle Valve Duty Cycle Adjustment - alters the idle valve duty cycle feedback with a proportional adjustment based on the slider position. If the idle tends to dip too low when releasing the throttle, increase the slider. If the idle speed tends to hang too high, decrease the slider.
The idle target lambda sets the air fuel ratio while hot idling. With large injectors it may be necessary to enrichen the hot idle to prevent lean misfires.
Ignition Controlled Idle
At idle the ECU will adjust the ignition timing in order to maintain a steady idle. The ignition adjustment depends on the difference between the target idle and actual engine speed. When the engine speed is higher than the target idle, ignition timing is retarded; when lower ignition timing is advanced.
The adjustment tables control the amount of ignition retard (when the rpm is higher than target idle) and advance (when the rpm is lower than the target idle). The table index is the difference between the target idle and engine speed. The table value is the amount of ignition retard (or advance).
The range controls the maximum advance amount when the rpm is lower than the target idle.