Date: Sat, 19 Feb 2005 22:41:17 -0500
Reply-To: "Adam H. Behle" <tikiman2@COX.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "Adam H. Behle" <tikiman2@COX.NET>
Subject: Re: AFM ADJUSTING
Generally, the o2 sensor seemed to be doing its job-cutting out on decelleration, showing more
voltage under loads and up grades, etc. It did have a hard time dropping the voltage after going
over a grade or accelerating quickly.
The initial "rich and sooty" position of the AFM wheel was about 7 clicks counterclockwise of the
original position and gave a reading of about 800 mv while cruising at 3000 rpm on level ground.
As I turned the wheel clockwise and monitored each new position while driving,
the engine seemed to be leaning out a bit with each click clockwise, but the idle would stay
around 2000-sometimes dropping slowly to 1000 or so. The voltage or engine behavior did not
seem to change whether the wheel was 5 clicks or 20 clicks clockwise. I would get a reading
around 500 mv at idle, but it was usually around 650 in normal driving and at idle! I'll try some
more tests and take more detailed notes in the next few days-the rain has been pretty nasty.
o2 sensor was cleaned before all this, but it's probably pretty gunked up again after all this fooling
around. It is the 3-wire type, and I connected the black 16G lead to the red mm test lead and
connected the other mm lead to ground. Unfortunately I have 2 nasty hairline cracks on 2 of my
exhaust headers-both on the right side. So perhaps all the o2 testing is pointless until I replace
(gulp) those headers. The van had been running fine (ok, a little rich) before with the cracks
though.
I guess I'll try leaning out the engine a bit and start adjusting the idle a bit. It is tempting to just
order a rebuilt unit at this point and slap it in, followed by a new exhaust-but I have a hard time
justifying all that cash to fix a funky idle. I think I am finally committed to a decision to keep the
wasserboxer platform rather than a Subaru due to time, space, and potential resale issues-so
"investing" in this engine might not be so bad. Bostig Engineering's miracle air box sounds really
interesting as well if it actually materializes.
Thanks again for your prompt replies,
Adam
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