Date: Sun, 23 Sep 2007 15:16:23 -0400
Reply-To: pdooley <psdooley@VERIZON.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: pdooley <psdooley@VERIZON.NET>
Subject: Re: Replacement AFM technology
In-Reply-To: <13e501c7fe14$3396cb70$6401a8c0@TOSHIBALAP>
Content-type: text/plain; charset=US-ASCII
Exactly.
Speed density with a simple, inexpensive MAP sensor.
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Scott Daniel - Shazam
Sent: Sunday, September 23, 2007 3:02 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Replacement AFM technology
Would you want to buy a used/old/maybe dead one to experiment with, take
apart etc ?
Scott
www.turbovans.com
PS - I'd be looking for a way to use an air mass meter myself - to retro fit
that newer much better device.
Or even eliminate it entirely - check out Honda's for example - multi-point
EFI - no air mass or air flow meter. GM too, many other manufactures too.
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
tinker man
Sent: Sunday, September 23, 2007 3:02 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Replacement AFM technology
Once again, me and my crazy ideas...
With all the potential problems we're facing in our vans in general
and it's fuel injection system specifically (which is most hard to
debug in the van, with no on-board diagnostics support), the one I'd
most want to get rid of is the AFM, who's mechanical deterioration is
the hardest to fix, and finding a replacement is getting harder and
harder (and expensive too, $200 just for a remanufactured unit).
I remember reading lots of talk about this on the list, and wonder if
after all the talk someone has actually come up with an alternative?
So to get things going, a few questions:
1. Has anyone measured (or has the data of) the AFM transfer function,
i.e. resistance or voltage output vs. air flow? For that matter, even
a graph/table of resistance values/output voltage vs. sensor plate
movement would be helpful (it's probably logarithmic). Bentley
provides a graph just for the temp1 sensor vs. temperature, but non
for the variable resistance vs. air flow.
2. Anyone know what maximal airflow is to be expected in the air intake
path?
3. Since I don't have a spare AFM to play with, does anyone have high
resolution pics of an opened AFM? What's the function of the three
black rings located around the pivot?
4. Does anyone know if the re manufactured AFM's offered at the
BusDepot and others have a NEW resistance board or is it just the
simple fix of moving the old one a bit sideways?
Thanks,
TM