Date: Sun, 16 Sep 2007 08:09:27 -0400
Reply-To: Raymond Paquette <raymondpaquette@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Raymond Paquette <raymondpaquette@GMAIL.COM>
Subject: Re: Rich on side, lean the other?
In-Reply-To: <062c01c7f82e$acd7b3f0$6401a8c0@TOSHIBALAP>
Content-Type: text/plain; charset=ISO-8859-1
Scott
Can you explain this? It would seem to me that if the injectors all fires
at once, then three cylinders would get gas when they weren't meant to be
firing.
What am I missing?
Ray
On 9/16/07, Scott Daniel - Shazam <scottdaniel@turbovans.com> wrote:
>
> The ECU can't run any injectors richer than any others.
> It fires the 4 injectors at once, by supplying ground to them.
> It treats the injectors as one big injector in 4 parts.
> The Oxygen sensor is a good thought - it's very easy to measure their
> output
> with a digital voltmeter. If it's been on there several years, it could be
> due anyway.
>
> I can't think of why one side would run rich and the other learner.
> You could swap the injectors side to side and see if the problem follows
> the
> injectors, or stays in the same place.
> You could observe the spray pattern in accordance with the Bentley manual
> too.
> Scott
> www.turbovans.com
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Michael Elliott
> Sent: Saturday, September 15, 2007 4:59 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Rich on side, lean the other?
>
> I'm hunting for the reason that Mellow Yellow gets about 15% poorer
> mileage than other similar vans. See
>
> http://camping.elliott.googlepages.com/poormileage
>
> to see what I've learned so far about this 1.9L 1984 auto transmission
> with only 75,000 miles on it.
>
> One oddness I've found is that both plugs on the passenger side indicate
> lean condition, while the plugs on driver's side indicate rich condition.
> Where could such an asymmetry come from?
>
> There are NO visible signs of air leaks. The intake runners don't have any
> cracks, are tightened well against heads; the plenum/runner sleeves are
> clean and intact; and there are NO cracks in the exhaust bits that might
> cause a false-lean reading at the O2 sensor -- this is a southern
> California car and we outlawed snow and salt in 1932.
>
> This lateral mixture imbalance has me quite puzzled. I am getting little
> fret marks between my eyebrows! I'm dumping in a buttload of Techron
> injector cleaner in case the injectors on the lean side are packed up and
> the ECU is overcompensating by running #3 and #4 rich.
>
> But . . . and but, the overall mix at the O2 sensor indicates /lean/ on
> the highway, oddly (see http://camping.elliott.googlepages.com/poormileage
> ).
>
> I am replacing the O2 sensor on Monday. Because.
>
> --
> Mike "Rocket J Squirrel" Elliott
> 71 Type 2: the Wonderbus
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
> KG6RCR
>
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