Up Up and Away

[Bill the arcstarter]

Phil Lamovie <phil at injec.com> wrote:

>The very simple point to be had here is that next time the same air
>temp and pressure are found at the same rpm then the same stored
>values for fuel and spark will of course produce the same A/F ratio.

Thats how I see it.

>Note how I completely left out the throttle position. It may be that
>at 15,000 feet ASL the WOT pressure will be only 70 kPa. If the engine is 
>at 3000 rpm and the air temp is the same the Volumetric efficiency of the 
>engine is the same.

For systems equipped with either mass air flow or MAP, my understanding is 
that the TPS is only used for limp-home mode, determination of WOT vs run vs 
idle states, and enrichment/leanment during rapid transitions.

>Please note the total lack of Patents for Altitude correction of
>aircraft fuel injection computers. Also total lack of altitude sensors on 
>all Ford and GM vehicles. I suppose they don't have mountains in the USA.

Hmm.  Could the O2 sensor closed loop operation account for this?

Or - altitude could be faked out by reading the MAP while the engine is 
stopped.  Then you could account for it.  Of course this assumes that the 
car is stopped every once in awhile (probbaly a reasonable thing).  I know 
for a fact that some outboard marine engine controllers do this.

-Bill
'84 Suburban w/ 350 w/ Holley-4Di

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