>>>There may be some automatic mixture adjustment built into the F/I
>>>but it is probably small....

I thought altitude compensation was handled by the fact that
the less-dense air moved the AFM vane less and so requested
less gas to be injected.  Not so?

[BTW--I remember some GM info in the mid-sixties that effective
power at the wheels was reduced 25% at 5000' and 50% at 10000'.
Of course, this was big iron, carbs and automatics!  But it has
always seem roughly true in my four buses, '61, '67, '76, '81.]

                                Richard A. Jones
                                Boulder, Colorado
                                '81 Vanagon  Mr Bus

PS: Mr Bus summits Nebraska!  http://coyote.colorado.edu/jones/nebr.jpg