Function of map sensor

[Kb444fishing]

Have learned so much from the smart guys on here. So here is another one what does the map sensor do on a opti max? Could it have any function toward fuel flow.

[lpugh]

Manifold Absolute Pressure, Sea levels is 14.7 psi, A perfect vacuum of almost 30 in hg is O psi, PCM uses the map to determine load on the motor, with MAP, TPS, ACT ( or IAT intake air temp) and RPM the the PCM can determine air charge speed/density) At key on the map sees atmospheric pressure (Barometric), which is also used in this calculation, With this information the PCM can calculate the amount of time the injector must be open to deliver the proper air fuel ratio for the work being performed
Years ago we worked on motors in terms of vacuum, now days absolute pressures, Vacuum is a term to describe something we don't have and that is pressure, you will notice the about 2-1 inverse relationship. Lets say a motor is idling at 15 in hg which means it has about 7.5 psi absolute pressure, Offers simpler way to understand air charging when thought in terms of the actual pressure doing the work (not vacuum, This becomes much easier to write software especially when their are turbos and superchargers that can provide upwards of 30 psi absolute, A vacuum sensor can not do that
This is the simple answer, it does get quite involved

[EuropeanAM]

Another way to look at it: Your engine's fuel management system is a SPEED-DENSITY system.

The Crank Sensor provides the SPEED (RPM) info.

The MAP Sensor provides the DENSITY information.

Everything else is "fine-tuning" from various tables in the PCM's programming.