Date: Tue, 7 Jun 2005 09:07:57 -0400
Reply-To: The Bus Depot <vanagon@BUSDEPOT.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: The Bus Depot <vanagon@BUSDEPOT.COM>
Subject: Re: oops, more questions on O2 sensors
In-Reply-To: <000001c56b14$000e1cd0$6400a8c0@masterpc>
Content-Type: text/plain; charset="us-ascii"
> I have been driving Matilda with the O2 sensor disconnected since
> great. the new Boston Bob engine went in. Then I remembered that
> the O2 sensor wasn't connected, so I reconnected it. Then she ran
> doggy. Disconnected it again and she runs fine. Which seems like
> good evidence that the O2 sensor got fried when the old engine did.
Likely, but there could be other issues. If I'm not mistaken, disconnecting
just one sensor from the circuit (such as the oxygen sensor) causes the ECU
to stop reading various input signals and instead revert to factory-preset
mode. Kind of a "limp home" feature. (And a welcome one. On aircooled F.I.
models, if your temp sensor lost its ground your engine wouldn't run at
all!) So this is how you have been running your van. I've done it myself in
a pinch, but that's about all it's good for. It will run well enough to get
you by, but not right. I don't recall exactly which inputs the ECU stops
reading when in default mode. Dennis mentioned the temp 2 sender and I'm
sure this is one of them. Not sure what else if anything. I run into this
periodically when someone thinks their new 02 sensor is defective because
their van runs worse with it than without it. The reason is that by
unplugging it and going to default mode they masked another problem.
> The universal Bosch sensors properly spliced usually work fine.
That would be this:
http://busdepot.com/details.jsp?partnumber=15725
It comes with a waterproof splicing kit for splicing your old harness plug
to the end of it. No real reason to spend the $$$$$$ for the one with the VW
connector as long as you do a good job splicing on your old plug.
While the above kit is more convenient since it's a pre-packaged solution,
you can also get the same sensor with a Ford plug on the end (which you cut
off) and no splicing kit, for a little less:
http://busdepot.com/details.jsp?partnumber=13913
> Also, the O2 sensor should have a heat shield/deflector
> on it so that it stays hot and road spray doesn't get to it.
> I'll bet the shield is missing.
Here: http://busdepot.com/details.jsp?partnumber=035906274
- Ron Salmon
The Bus Depot, Inc.
www.busdepot.com
(215) 234-VWVW
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