programming for a MAF based system

[Eric Fahlgren]

les wrote:
> 
> Can someone point me to any hints for how to approach the
> algorithms for fuel calculations, as they apply to a mass air
> flow measuring fuel system?
> 
> At first look, it seems that all the 'normal' variables needed for
> MAP systems just drop out of the equation. I suppose that I still need
> a 2d map , to allow for richening under boost, but it just seems too
> simple. I mean, other that for idle speed needs, rpm doesn't even seem
> to enter the equation. Air mass is air mass.
> I understand that the MAF is not linear, but a simple lookup table
> should
> fix that.

Les,

Are you working with a true _MASS_ air meter, not an AFM which
produces some uncorrected value?  In that case, just have a 1D
map which relates mass to AFR and from that calculate a pulse
width.  If not, you need temperature correction (at least) to
get mass, then use the table.  Should be pretty simple compared
to the 2d VE tables usually used with speed density.

All the usual gamma terms still apply same as with MAP systems,
acceleration enrichment, cold start/warmup and so on.

Eric

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