Originally Posted by space
Can't this be picked up from the lambda sensor? If the air is thinner than expected and the stoichiometry is off as a result, then the lambda sensor should detect that the engine is running too rich and adjust accordingly. Or vice versa for "too thick" air.
That would only work during closed loop operation, though. I'm not sure how this works during non-steady-state conditions. I defer to the tuner gurus on this thread....
There are experts and I am not one BUT - I am pretty sure (anyone know for sure?) that most all current ECU's have a air density sensor within the ECU housing - that has been my experience and it is essential to have that to compare - air temp - air density - with the lambda which is post combustion. As air density is not completely corolated with air temp. ie. hot and high altitude. Moisture content... weather systems....