Date: Wed, 23 May 2001 23:17:38 -0600
Reply-To: Steve Blackham <steph@uswest.net>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Steve Blackham <steph@uswest.net>
Subject: Re: Analyzer question
Content-Type: text/plain; charset="us-ascii" ; format="flowed"
Pat:
I bought one last month and have been going to report to the list
its effectiveness as soon as I can thoroughly test it and become
competent in its operation. I don't feel I am there yet but with
your query I feel I must give a preliminary response.
I ordered the basic model (CO only) for $170. They shipped me the
"deluxe" model (listed for $250) for the same cost. This model is a
dwell, tach and volt meter also. It arrived promptly within a few
days which is not normal for my previous experience with JCW.
I began using this unit to diagnose my 87 Vanagon's richness and HC
problem. At first this was a frustrating process. You first have to
calibrate the unit to outside air and a 2% calibration. Because It
kept coming up with high CO figures I originally questioned the
accurracy of this unit. Finally when my family brought home other
vehicles with what I feel were accurately in spec CO readings I
determined that the unit was indeed accurate and would read CO under
1% somewhat accurately.
I finally found the problems with my 87 and it confirmed that these
corrections did indeed bring it into spec. So far I would have to
say that the unit does indeed work. Having said that, I wouldn't at
this time recommend anyone else buy one. First it's construction is
crap. Very cheap plastic. Very poor construction. What it actually
is and does is not worth this kind of money. They have taken a
similar technology to a lambda sensor and just fitted it with a
metered read out. I have seen better dwell/tach, and volt meters for
less than $30. Let me repeat though that it does appear to work. I
am satisfied for my use that I didn't get taken to much in its
purchase. I say this because I have 12 vehicles with different
emmissions systems for which a simple O2 sensor and Volt meter won't
work or at least be convenient.
I would not recommend this unit to others though. First, a cheaper
and just as efficient means of testing a closed loop system is
applying a good digital volt meter (say $40) to the O2 sensor
circuit. I welded a 18 mm threaded insert to my 77 Bus's exhaust
manifold and it gives me just as accurate idea of CO output /
richness as this unit does and it costs under $30. The problem is
neither shows HC content and to accurately set up your FI sytem you
need to balance each.
If any one is interested in doing their own CO adjustments I would
recommend first reading the Bosch FI articles in the bay window
library. If you are still interested I would recommend reading two
books available at you favorite "free, public" library---Barnes and
Noble:" Bosch FI & Engine Management" by Charles Probst and "How to
Tune & Modify Bosch FI" by Ben Watson. I know Digifant is not Bosch
but it is very close to Bosch Mototronic and is also the successor to
Bosch L Jetronic and the same principles apply. In the chapters in
these that have to do with basic emmissions sciense is very
interesting and if studied will give you a better idea what the
relationship is between CO, HC, and NOx before and after a CAT.
Anyone local I would be glad to use this unit to test your FI. I
won't lend it out because I fear this unit is to fragile to come back
in one piece.
Steve
Original message
Date: Wed, 23 May 2001 14:45:54 -0700
From: Pat Callaghan <patcal@qwest.net>
Subject: Analyzer question
I am considering buying a exhaust analyzer. There is one at JC Whitney MDL
#12ZX5486B that I am thinking about. Anybody have any experience with this
or any other consumer model? Are they accurate? It sure would seem to save
me some money. About the only reason I go to mechanics is for the CO
adjustment. This model is also a ignition/battery tester. Thanks.
Pat Callaghan
82 Westy
Portland, OR.
http://www.users.qwest.net/~patcal
--
Steve Blackham
Centerville, Utah
77 transporter converted to camper (Westy top)
83 Vanagon (New and current project)
87 Weekender
