peugeot-L@yahoogroups.com wrote: Simplest way of looking at Logarithmic and Linear.
Logarithmic is in steps like stairs.
Linear is an even curve much like a conveyor belt.
Dave
Skoda Superb TDi 2005
206 LXi 1999
Clio 1994
Message: 2
Date: Tue, 13 Dec 2005 09:37:19 -0600
From: "Bob Bruce"
Subject: Re: Re: 505 Turbo AFM checks
Bosch info states that these AFMs are logrithmic rather than linear
if anybody knows what that means
Apparently this explains to the whizes why the resistance readings are
not what you might expect as in a light dimmer
Bob
Message: 6
Date: Tue, 13 Dec 2005 10:38:54 -0800
From: august
Subject: Re: Re: 505 Turbo AFM checks
Interesting Bob, thanks for that info, your totally right.. I did a
little research and found the same thing:
Right from the Bosch book of Automotive Fuel Injection Systems Technical Guide:
Page 100
"The relationship between the mass airflow and the flap angle is
logarithmic, which ensures a non linear characteristic in the
potentiometer."
i take it logarithmic means its not linear (obviously), but it will
fluctuate during the complete sweep of the flap.
I asked another friend / peugeot homie who said:
"it should read the highest value when the flapper reaches to most
deflection it can attain with airflow pushing on it"
Bob, is the AFM you have for sale new? Would you be able to test it?
On 12/13/05, Bob Bruce wrote:
> Bosch info states that these AFMs are logrithmic rather than linear
> if anybody knows what that means
> Apparently this explains to the whizes why the resistance readings are
> not what you might expect as in a light dimmer
>
> Bob
>
> PS I have a spare turbo AFM forsale with airfilter and box
> ----- Original Message -----
> From: Bill
> To: peugeot-L@yahoogroups.com
> Sent: Tuesday, December 13, 2005 12:07 AM
> Subject: [Peugeot-L] Re: 505 Turbo AFM checks
>
>
> I've seen the same behavior on different units.
>
> -Bill
>
> --- In peugeot-L@yahoogroups.com, august wrote:
> >
> > There's one test shown in the N9T/N9TE/N9TEA for checking the AFM:
> >
> > Connect an ohmmeter between pin 5 and pin 7 of the AFM. Then move the
> > flap door slowly to full open.
> >
> > It says it should be between 60 and 1000 ohms.
> >
> > Now, I've done this test on 4 AFM's. You'd think that whatever the
> > value the book was calling for would be a clean sweep from low (full
> > shut), to high (full open). Not the case, on all FOUR that I have.
> > They seem to jump around a lot. As the doors opens, the value rises,
> > but can go up and down, and full open on all isn't the peak value.
> >
> > (more like, 60(door closed), 100, 300, 150, 500, 800, 200, 900, 400
> > (full open))
> >
> > Is this normal, or do I have a bunch of bunk AFM's?
> >
> > Here's a sample reading:
> >
> > full shut: 80
> > peak: 1000
> > full open: 450
> >
> > Do any of you have experience with this? Or would any of you be
> > willing to test the AFM's you have? I've been looking around the net
> > to try to educate myself on exactley how these things work, but
> > haven't found anything on super bouncy readings.
> >
> > thanks!
> > /august
> >
Yahoo! Cars NEW - sell your car and browse thousands of new and used cars online search now
[Non-text portions of this message have been removed]
Recommended format for your email subject lines:
Model # [Model Letters] Year Subject
Examples:
505 88 V6 Mileage
405 Mi16 89 Ignition Coil source?
To unsubscribe from this list send a blank email message to PEUGEOT-L-UNSUBSCRIBE@EGROUPS.COM
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/peugeot-L/
<*> To unsubscribe from this group, send an email to:
peugeot-L-unsubscribe@yahoogroups.com
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
Received on Wed Dec 14 13:30:12 2005
