While doing more fine tuning, i have a question that I just can't seem to word right or get a straight answer about.
Example: My ECU has an Air Temperature Modifier to add/remove fuel based on the density of air. In this case at 36*F its adding 7% fuel. Now, at cruise, my Oxygen Sensor is trying to achieve 15:1 AFR. The result I see is that the Oxygen Sensor and the Air Temperature Modifier are fighting each other. My engine normally operates at a Closed Loop Compensation around 92%, but I can see it removing more when the modifiers are in play.
So in my head, the reason additional fuel is added at all (coolant or air temp modifiers) is because the fuel comes out of suspension or is not atomized enough to be burned completely. I would expect this to mean that the additional fuel is there to MAINTAIN the desired AFR. Meaning that the extra unburnt fuel should not reflected in the oxygen sensors readings.
What I have been told is the opposite; that the additional fuel results in a lower AFR (like during warm up when I run roughly a 11-12 AFR). My head isn't quite wrapping around this. What is the point of having modifiers active when the oxygen sensor is running at all if it's just going to fight them anyway?
OR am I interpreting my Closed Loop Compensation wrong and its NOT removing the fuel that the modifiers are adding?
This question is mostly for Air Temperature modifiers. Unlike engine Coolant Temperature Modifiers, Air Temperature modifiers are based on a very standard engineering curve for Air Density. I already have tuned my ECU to stop adding any Coolant Modifiers once Closed Loop Compensation is engaged (at 145*f Coolant Temp), but Air Temperature Modifiers should be in play all the time.