Still plugging away at the 1uz PCM, however work is slowing things down. Here's a little suprise, there's a MAP sensor inside the PCM, sensing atmospheric pressure. So I guess that means it's NOT a MAP sensor, because it's not sensing manifold pressure, but it's basically the same part.

The little hole that the arrow points to is so air can get at the sensing element, which is under a clear cover of all things.

The PCM needs this value as the karman vortex AFM fundamentally senses air speed, not density rate, and the chemistry of combustion requires knowledge of the actual mass of air inside the engine. The measurement from this sensor, along with the air temp sensor are used to compensate the AFM measurement to get a mass flow value.

and on a side note I've figured out most of the fueling algorithm, however the oxygen sensor corrections have eluded me thus far. Most recent update is hit to Git(hub) and volunteers are always welcome!