Explain ASE Taper to me
 

Let's say I have an ASE Taper curve that has 50 degrees coolant temp gets 300 cycles of taper. If she idles at 900 rpm, it should take ~20 secs to taper off. Less if the car gets moving. But if 70 degrees has 280 cycles (or whatever), does the curve start over if the temp reaches 70 degrees before the 20 secs are up?

It's possible I have the cycles thing wrong, but I don't see a way to change from cycles to secs.

Thanks.

ASE adder and ASE taper work in concert with one another. The way I understand it, the ECU does a one time lookup of the CLT and then determines how much percent extra fuel to add (ASE adder) at that temperature and for how long that extra fuel should be added for (ASE taper). If you specify 50% extra fuel at 50°F and 300 cycles to taper, then the ECU will add 50% more fuel than your VE table would normally command at t0 (the time at which your ECU switches from cranking to run). The % of fuel added decreases in a linear fashion until it reaches 0% extra fuel at t1 (the time equivalent to the number of seconds or the number of cycles you have specified in the ASE taper menu). To change from seconds to ignition cycles or vise versa, go to Startup / Idle > Cranking / Startup settings > ASE Count Units.

Excellent. Thanks much.

Cycles is the proper way to do it, IMO. You want to pull ASE faster if you are driving the car and generating more heat vs. just letting it idle.

Agreed. It just seemed odd that within that particular menu, I could not change from cycles to seconds.