Date:         Sat, 28 Apr 2001 07:50:21 -0800
Reply-To:     Mark Keller <kelphoto@islandnet.com>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Mark Keller <kelphoto@islandnet.com>
Subject:      Fuel Injection Adjustment/ High CO at idle
Comments: To: Steve Blackham <steph@uswest.net>
Content-Type: text/plain; charset=us-ascii

Hi Steve,

Congratulations on taking this project, It gave me great satisfaction to
learn exactly how my system worked. I'd be interested in the correlation
between the CO meter and the O2 output voltage when you get a chance to
compare them.

As to your questions, I wrote quite a bit about the fuel injection
system when I was on the project.  Look under my name, Mark Keller, at
www.gerry.vanagon.com, in the last two years.

As to the High CO at idle, I believe the best thing is to realize that
the Fuel control system is dependent on fuel pressure as a preprogrammed
value; so if your injection system is higher or lower fuel pressure
value because of: timing, vacuum leaks, worn parts, etc., then the
system has a built in error in the fuel injection map.  I say this
because I originally didn't know this. I believe that verifying the Fuel
injection pressure regulator and such is the first step. Since
hypothetically anything that contributes to a low vacuum signal to the
fuel pressure regulator could cause the fuel pressure to be higher that
the pre-programmed values.

Having said that, The Fuel injection voltage signal from the AFM can be
tweaked by repositioning the wiper arm.  In fact a good wiper arm/
carbon track maintenance is a excellent second step in your project.
The job is straight forward, but loctited screws complicate it.  Oblong
the holes in the circuit board to relocate the wiper arm contact to a
new position, clean with a electronics type spray.

Spring tension is the next step.  I don't know the exact Pro Training
Manual Values, these are approximate. Disconnect the O2 sensor and
monitor its voltage while driving at a steady 3000 RpM, driving
conditions, read the voltage on a multimeter and aim for a spring
tension that gives you around .7 volts. Then you can go to working on
Idle adjustments.

Sincerely,

Mark Keller
91 Carat
Cowichan Bay, BC