Idle spark enable/disable by VSS?

[DrX]

Is idle control by spark disabled by hitting a defined speed? I can't seem to find this in the tune. My truck will idle all day in N or in gear stopped, but as soon as I roll down the driveway it wants to stall. Just did a log and found that the stall coincides with spark control of idle shutting down around 4 kmh. I can keep it running by doubling my Desired Airflow table, but then I don't need cruise control anymore.

Log and tune attached.

[joecar]

See descriptions for B0107 and B0108, is this what you mean...?

[DrX]

I looked at those and they are both set to 0 in my factory tune. It seemed that if they influenced control of idle by spark it should never be active as ETC TP is always greater than 0, unless B0108 is ignored on ETC vehicles. Also it doesn't cut out until VSS reaches 4-5 kmh. The problem is that it doesn't seem to re-enable until VSS is 0.

I guess what I was really looking for was a re-enable speed as there seems to be a disable speed. I will try changing B0107 to test whether it has any effect. I am also decreasing B4506.

[DrX]

Just did a couple of very short logs. First (516)with B4506 lowered to .3 sec. Then(517) also changed B0107 to 4 kmh. Not sure that either did make any difference.

I did notice that spark idle control will re-enable before 0 kmh if TP drops below 10%. Similarly, it will disable before 5 kmh if TP exceeds 10%. So 5 kmh and 10% TP seem to be the triggers.

Looking at my tune, I also noticed that Throttle Cracker airflow kicks in at 5 kmh also....right where the engine starts to stumble.