Hondata

Hey All,

Trying to learn a few things about tuning...need some input...

On cold start up...the AFR seems to fluctuate quite a bit and then level out...by my fuzzy math...here is what I think is happening.

1) car cranks and fires...o2 sensor takes a bit to warm up and read the AFR
2) car uses open loop values from low fuel tables until o2 sensor warms up
3) once o2 sensor is at operational temp and is reading correctly, ecu switches to clopsed loop and adjusts to get the car back to its target AFR.

my question is, can someone explain whats going on, am i right and is it normal? Trying to learn as much as I can....thanks in advance.

This looks like pretty normal behavior and that's why you must delay using closed loop from a wideband until the O2 heater has a chance to warm up.

Keep in mind that you also have target lambda limits by ECT settings, when the ECT is low that usually triggers and differs from your overall lambda target as well as the fuel compensation tables based on ECT and IAT, so there is a lot more going on under the hood.

Spunkster wrote: Wed Feb 21, 2018 11:23 am This looks like pretty normal behavior and that's why you must delay using closed loop from a wideband until the O2 heater has a chance to warm up.

Awesome...is there a benefit/possibility in KProV4 to increase the duration of open loop operation during the cold start period? A friend said you could but i am curious if this is even necessary.

Thanks!!!

creizlein wrote: Wed Feb 21, 2018 1:12 pm Keep in mind that you also have target lambda limits by ECT settings, when the ECT is low that usually triggers and differs from your overall lambda target as well as the fuel compensation tables based on ECT and IAT, so there is a lot more going on under the hood.

I see...in order to warm up the motor prior to driving the car right?

Thanks!

That is also correct.