Date: Mon, 27 Apr 2009 01:02:00 -0600
Reply-To: Paul Connelly <vanagonhummingbird@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Paul Connelly <vanagonhummingbird@GMAIL.COM>
Subject: Re: O2 Sensor?
In-Reply-To: <49f4fd65.2035640a.7ee9.4db8@mx.google.com>
Content-Type: text/plain; charset=ISO-8859-1
Thank''s David,
Those were my thoughts, but looking for some reinforcement. May have some
issues actually doing the physical change being burned in there and all, but
would like to have the back up ready! The difference (if any) between the
pre programmed mixture setting and the closed loop system provided with the
O2 sensor (especially at this elevation) might be interesting.
Cheers, Paul,
On Sun, Apr 26, 2009 at 6:33 PM, David Beierl <dbeierl@attglobal.net> wrote:
> Hi Paul --
> At 01:41 PM 4/26/2009, Paul Connelly wrote:
>
>> waiting for replacements to arrive). Checked the voltage output from the
>> O2
>> sensor (disconnected) and just wildly varies from about .05V to about
>> .15V,
>> nowhere near the .45V ish that it should be (or the .8V to be running that
>> rich).
>>
>
> The half-volt signal is actually driven from the ECU -- on the naked sensor
> will generally be either full high or full low or transitioning between the
> two. .05-.15v all counts as "lean" but isn't meaningful otherwise.
>
> If it's behaving the same way when it's hooked up, the ECU will drive the
> mixture extremely rich trying to get the sensor to flip over to "rich."
>
> So seems to be O2 is at least the most likely culprit.
>>
>
> If that's how it's behaving when it is connected then it is without
> question a culprit.
>
> get the first trip in next weekend, and would rather replace it than just
>> leave it disconnected to get a better idea of how she is running overall.
>>
>
> If you want to know how the van is running, leave the sensor disconnected.
> It can cause problems, and it can disguise problems, but it won't make a
> properly running engine run any better. The sole reason it's there is to
> tightly control the mixture for the benefit of the catalytic converter. So
> my advice would be at the first sign of any running trouble, disconnect the
> sensor first, and don't reconnect it until the problem is solved. Your
> emissions will temporarily go up some, but you'll be able to solve the
> problem without the sensor sticking its oar in and confusing things.
>
> --
> David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
> '89 Po' White Star "Scamp"
>
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