B5916 Base Spark Closed Throttle Threshold
B5917 Base Spark Vehicle Speed
I've been looking at timing during very low load in regards to surging/bucking issues lately and have been seeing some very interseting results. These results have brought me to look at these 2 cells.
Mine are set to:
B5916 = 1.191%
B5917 = 256mph
The descriptions are:
B5916: If the throttle is below this value and vehicle speed is below threshold, then it is considered closed and the base spark tables will be used
B5917: If the vehicle speed is below this value and the throttle is below threshold, then the base spark tables will be used.
I am using a drive by wire setup and my throttle position never goes below ~8%. However I do know that my pcm transitions from the high octane to base spark table. However, it seems that it oscillates between the 2 at the very low load. My throttle opening is somewhere around 10% when this occurs.
My question for B5916 is: It seems that in the case of drive by wire that this value is % of change or something else is controlling the transition. Is this the case?
My question for B5619 is: If this is set at maximum it would seem that the base spark table should be entered as soon as the pedal reaches the idle position. Why would I want to be using idle spark values with rolling air and fuel values?