I'm missing something...

Kris Weldy volvo4life at home.com
Wed Nov 14 01:45:57 GMT 2001


Why cant anyone make a gauge of some sort to measure how much cfm of air a
motor uses at various rpms?This sure would narrow down the chance for error
on turbo sizing and get one more familiar with what the engine is doing-same
for exhaust.Your friend,
Kris Weldy
Arlington Texas
88supra turbo auto 9.1 1/8th
aim :volvofam3
yahoo:supratheonlywaytofly
----- Original Message -----
From: "Bruce" <nacelp at bright.net>
To: <diy_efi at diy-efi.org>
Sent: Sunday, November 12, 2000 1:41 PM
Subject: Re: I'm missing something...


>
> MAP or MAF they are just used to calulate the air consumption of the
engine.
> Once you know how much air is being used, you can calulate how much fuel
to
> add to get a given AFR.
>
> The only feedback on O2 is from the O2 sensor (exhaust side of the
engine).
> Ambient O2 levels vary from location to location, and that isn't directly
> sensed for the fuel calulation.
> Bruce
>
>
> From: "Bob" <bob at scientist.com>
> Subject: Re: I'm missing something...
> > Isn't the reason for the MAP is to calculate the % Oxygen in
> > the air at different elevations?
> > MAF would still measure just the amount of Air entering the engine
> >  , even if it's Oxygen content is much lower at higher elevations...
> > or do I have it all wrong?
>
> > From: "NickG" <nikog at mediaone.net>
> > To: <diy_efi at diy-efi.org>
> > Sent: Sunday, November 11, 2001 8:44 AM
> > Subject: Re: I'm missing something...
> > > A flapper door AFM can not compensate for changes in air density. The
> AFMs
> > > are 'airflow meters', but not 'mass airflow meters' like the current
> mass
> > > air meters. Thus, changes in elevation are not detected. That is why
the
> car
> > > in question started running rich at higher elevations.
> > > But, I would have expected the ECU to tempensate and adjust the
mixture
> > > based on the O2 sensor's feedback. Unless, of course, the system is
> > > programmed to run in open loop or has adaption turned off.
> > > Nick
>
>
> ----- End of forwarded message from owner-diy_efi at diy-efi.org -----
> --------------------------------------------------------------------------
--
> To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the
quotes)
> in the body of a message (not the subject) to majordomo at lists.diy-efi.org
>
>

----- End of forwarded message from owner-diy_efi at diy-efi.org -----
----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org




More information about the Diy_efi mailing list