Hi Mark and All,
    Abandoning  fuel injection for a carburetor is about as logical
 as my grandfather who refused to ever drive a car or tractor again
 because it never stopped when he hollered whoooooa as he drove
  through the back of the barn about a century ago. Horses worked
 fine in the old country and they work here also he would say.  He
 was an  expert horseman and his were always very healthy, strong
 and loved to work (well tuned).
         On another note I have found it very difficult to tune and
 obtain a good mixture by using just the afm (air flow meter) and
 open loop, no o2 (oxygen) sensor. The afm main spring tension
 constantly needs tweaked for conditions like altitude, gas (gasohol,
 oxygenated,  winter /  summer blend etc) constantly changing.
   The  mixture will vary quite a bit without an o2 sensor.  I like
 the idea of a near perfect mixture for many reasons, so much so
 I installed an 81 vanagon California  fi (fuel injection) system
 with o2 sensor on our 78 westy bus 2L (which came stock with
 an open loop system) .  It runs better and the  afm tuning is not as
 critical.  I usually set the afm main spring tension for an open loop
 o2 voltage of about 0.7 volts or slightly less. Then when  hammered
 down (forcing open loop) it has a good power mixture.

Darrell Boehler

ps. The story about my grandfather is true.

----- Original Message -----
From: "Mark Ingalls" <ingalls_mark@HOTMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, March 07, 2001 6:46 AM
Subject: Re: O2 sensor stuff

> Bosch's closed loop system is a big advancement over carburetors or  open
> loop FI systems. But I can understand why people abandon it after searching
> high and low for solutions to performance problems with our Vans.
>
> Mark Ingalls
> 85 GL/w digitool
>