AFM to MAP

[John Andrianakis]

WILMAN wrote:
> 
> I am trying to remove the airflow meter on my Bosch Motronic system and
> replace
> it with a MAP sensor. Has anybody done this before? Could anybody advise on
> 
> the wiring? Is the output from the AFM similar to MAP, in terms of voltage
> changes?
> 
> Wilman
Voltage outputs is usually the same 0-5v. But the afm measures
volume(flapper door style) or mass(heated wire or film) while the map
measures absolut manifold pressure.
To use the map to provide the ecu with a signal similar to the afm you
must take into account rpm and air temp(for replacing mass airflow
sensor) and use an equation or better yet a lookup table for the
conversion. I think all this can be accompliced with microcontroller
based circuit.
An idea to get values for the lookup table would be to datalog the
outputs of both sensors while running the car along with rpm.
Good luck.
John Andrianakis.