Date: Thu, 25 Sep 2014 19:53:55 -0700
Reply-To: Don Hanson <dhanson928@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Don Hanson <dhanson928@GMAIL.COM>
Subject: On going Oxygen sensor issues...
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Recently, the O2 sensor on my Digifant inline VW ABA motor stopped
functioning. I un-plugged it and confirmed it was in-operative, drove
around a few days without one. My gas mileage went from ~22mpg to 17mpg
for one tank while I was messing around and waiting for a new one..The
motor ran fine and strong, but it was thirsty in the Open Loop mode.
New O2 sensor came and I did a rather hurried and sloppy job of
splicing it in, with the existing wiring harness and shielded wire very
brittle with cracked insulation. It did work again, very well indeed, for
about a week and 900 miles...with my gas mileage going back up to it's
normal 23-25mpg. Then I again encountered mixture problems, with the van
going full rich...I again unplugged the Oxygen sensor and again it went to
good running but crappy mileage for another tank of fuel...20mpg this
time...
This time around, I thought to replace the whole wire between the
Oxygen sensor and the ECU with some shielded wire I sourced from Aircraft
Spruce online...But as I got ready to do that and cut into the original
wire sheathing (tin?) and the signal wire inside looked in great shape...So
I did a better job of splicing in a real bullet connector and left the
original wire in place (again) I put the extra sheathed wire in my
traveling parts kit for later...again...Lazy aren't I?
Then I went under and put a wrench on the O2 sensor...it was
loose....almost finger loose. I took it out and bench tested it..and it
was still working in top shape...a single wire Bosch, BTW. I bought
another anyhow, just in case this was faulty...at $23 from Van Cafe, they
are inexpensive... I went ahead an installed the new one and did a more
careful job on the wire splice and this time, I made sure to torque it in
properly... Perhaps it being loose was making it not have a proper ground
and that was the only problem I had...
Anyhow all is running great again and when I fill up I shall hopefully be
back to my regular fuel consumption rate again...Lesson learned? Do not
'rush through' these fiddley little electrical fuel injection sensor
problems...do it carefully and check your work...
And in my type of driving the single wire Bosch O2 sensor works just as
well as a heated one, I can not tell any difference at all and in fact my
fuel economy actually went up two mpg...but that is probably because the O2
single wire sensor was fresh and brand new and my heated one was probably
40k miles old..The guys at Van Cafe told me the single wire one would
interchange just fine...and they are right, I think.
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