How is the motor load calculated?

That such friends is my first consultation
I would like to know if someone of you knows how the motor load is calculated long ago had a trailblazer that accelerated everything marked well but in the scanner I marked Engine Load 89%... and finally they took it from the workshop like this failure ..
now I have a Mazda 626 1996 that I did not do well that we have revived almost everything and everything is well mechanically and electrically. With the scanner I see data line and almost everything good only Engine Load 90% and by accelerating poquito rises to 100% ..
I have seen in other cars several brands and models and communicates between them is Engine Load (3.4% - 30%) the values ​​never rise more than 35%.
Is the question anyone knows how the motor load is calculated? Engine Load
What strategy the PCM uses to realize this data

The little that you know is that the load calculates it based on the air entrance, that is, measurement by MAF or MAP, from there and certain air temperature and refigentant (2 values ​​plus) adding the position of the accelerator pedal already calculates what each injector must open, then there are other variables such as the detonation sensor, which advances or backs down, with which the power Injection (opening time or injection pulse), on all this depends on the motor, surely someone can explain all this better, if I am wrong to tell us, so we learn better. Greetings!!