Date:         Fri, 10 Sep 1999 10:39:01 -0500
Reply-To:     Darrell Boehler <midwesty@MIDWEST.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Darrell Boehler <midwesty@MIDWEST.NET>
Subject:      Re: Tighten-up your AFM
Comments: To: Mark McCulley <transporter99@HOTMAIL.COM>
Content-Type: text/plain; charset="iso-8859-1"

Hi Mark,
    You are correct. However the afm needs to be reasonably close or the ecu
will not be able to compensate / correct the mixture. Also it is critical
that the tension be correct when in open loop, or on older systems without
o2 sensors. (ecu reads the afm, temperature 1, temperature 2 sensors, and
determines the mixture without the o2) The system is in open loop during
warm up and when the o2 is unplugged or defective.
    There are many post in the archives about adjusting the afm main spring
tension  using the o2 voltage. Be sure all else, with the engine and engine
electronics, has been checked and in proper condition before adjusting the
afm.
Darrell Boehler

----- Original Message -----
From: Mark McCulley <transporter99@HOTMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Friday, September 10, 1999 9:42 AM
Subject: Re: Tighten-up your AFM


> Right, tightening the AFM spring is an attempt to run leaner and produce
> more power. Seems to me though that in a properly functioning FI system
the
> lean condition would be compensated for by the O2 sensor and ECU which try
> to maintain the "correct" air-fuel mixture.
>
> Mark McCulley
>
> >From: Bulley <gmbulley@BULLEY-HEWLETT.COM>
> >Reply-To: Bulley <gmbulley@BULLEY-HEWLETT.COM>
> >To: vanagon@GERRY.VANAGON.COM
> >Subject: Re: Tighten-up your AFM
> >Date: Fri, 10 Sep 1999 06:46:11 -0400
> >
> >By tightening the AFM spring, aren't you forcing the injection to
> >miscalculate the intake airflow, yielding a "lean" state? I love simple
> >solutions, but this one doesn't sound like such a swift idea. Anyone?
> >
> >G. Matthew Bulley
> >Director
> >Bulley-Hewlett & Associates
> >www.bulley-hewlett.com
> >Cary, NC USA
> >888.468.4880 tollfree
> >
> >
> >-----Original Message-----
> >From:   Scarlett Semko [SMTP:damosem@MAIL.MCO.BELLSOUTH.NET]
> >Sent:   Thursday, September 09, 1999 11:26 PM
> >To:     vanagon@GERRY.VANAGON.COM
> >Subject:        Tighten-up your AFM
> >
> >Let me tell ya,
> >
> >After almost a year of putting up with hesitation, rough running, and
> >the like I finally took off the AFM cover and wound up the spring, and
> >presto-chango, I have smoth running again. It's like magic.
> >
> >If you are experiencing any of the above syptoms, please, take off that
> >cover and tighten-up that spring.
> >
> >I don't remember who advised the list a while back to tighten-up, but if
> >your ever in Orlando, Florida I'll buy ya a beer, probably two.
> >
> >Thanks
> >Ron Semko
> >Orlando, Florida
> >1984 Vanagon with 200,000 plus miles, and running smooooooooooth
>
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