Date:         Mon, 1 Jun 2009 00:26:54 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: O2 sensor transition time
Comments: cc: Rocket J Squirrel <camping.elliott@GMAIL.COM>
In-Reply-To:  <7.1.0.9.0.20090509125535.07e5fc78@attglobal.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 02:27 PM 5/9/2009, David Beierl wrote:
>At 11:32 AM 5/9/2009, Rocket J Squirrel wrote:
>>For the record, my O2 sensor cycles at 126 beats per minute according to
>>my metronome. That's 2 cycles per second in a 1.9L @ 3000 rpm.
>
>And 124 transitions in sixty seconds elapsed, 2.1l @3000
>rpm.  140,000 miles, old sensor -- unknown whether original.

Well, I replaced the sensor with an NGK "generic" one.  Immediately I
noticed that the transition times were snappier at low rpm, and that
the transition was faster going from lean to rich.  I finally did the
3,000 rpm check (idling) and got 160 transitions in sixty
seconds.  The NGK sensor has larger gas ports at the active end,
dunno if this makes a difference.

I also have observed that the ECU behavior is sensitive to load as
well as to rpm.  Running up a slight upgrade in top gear at about
3400 rpm/60 mph I counted about 260 transitions per minute.

  --
David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
'89 Po' White Star "Scamp"