[Gmecm] $58 Baro code

[Dig]

Had another what-if kinda idea....

Hook a dual-port boost solenoid up to the MAP, leave one port vented.
Periodically during the MAP read (maybe once every couple of hundred loops) , latch the last MAP value, flip the solenoid over to vent, and do a read.

Big question is how fast this could all happen, as the solenoids are pretty slow.

Later,

Dig 

----- Original Message ----
From: Scot Sealander <ssealander at Stny.rr.com>
To: gmecm at diy-efi.org
Sent: Friday, July 27, 2007 9:09:16 AM
Subject: RE: [Gmecm] $58 Baro code

The baro is reset with the engine not running.

I would not even bother with trying to reset the baro while running using
the 3 bar sensor.  The method GM used would force you to have to fill in the
BP reset table with different values with every different engine combination
it is used on.  And I would bet that it would not be all that accurate.

Just use a 1 bar MAP sensor that is reading the ambient pressure, and read
baro directly anytime you want.  You will have to check a number of 1 bar
MAP sensors to get one that reads accurately.  I found that I could get ones
that read from 95 to 100 kPa at my altitude.  I think that I am at about
600-700 feet.  I am not sure that a 2-3 percent difference in baro is going
to make that much difference in the fueling calculation though.

Scot

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