Date: Mon, 5 Feb 2007 10:05:47 -0800
Reply-To: Old Volks Home <oldvolkshome@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Old Volks Home <oldvolkshome@GMAIL.COM>
Subject: Re: CSI: Vanagon...Smog results!
In-Reply-To: <e38ccfaadc21.45c73342@optonline.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Just a note:
The Green Box Idle Stabilizer is for 80-85 California Models,
83.5-84Federal Models, 251 906 083
The Black & sometimes Grey Box is for 85 Federal Models, 321 906 083
And as Dennis says, not that they're worth anything - they're usually more
trouble than they're worth ;-)
--
Jim Thompson
84 GL 1.9 "Gloria"
84 Westfalia 2.1 "Ole Putt"
73 K Ghia Coupe "Denise"
72 411 Station Wagon "Pug"
oldvolkshome@gmail.com
http://www.oldvolkshome.com
***********************************
On 2/5/07, Dennis Haynes <dhaynes@optonline.net> wrote:
>
> Below 1,000 rpm, air quantity and turbulence is too low to promote fuel
> mix. That is the main reason the idle ignition timing is designed to be so
> low. Advance the timing, and the fuel and air quantity has to be further
> reduced to maintain a low idle speed. As there is no after air injection
> reaction system, all combustion has to be in the engine or the Cat. Also,
> the proper spec is 850-950 rpm. Not 650. There are two versions of the idle
> stabilizer, Green and Black. I forget which but one of them does not do
> anything until the idle approaches 650. Virtually use less. The other one
> starts to advance the timing as the idle goes below 750. Still not much
> help.
>
> Dennis
>
>
> ----- Original Message -----
> From: William Greenamyer
> Date: Monday, February 5, 2007 8:22 am
> Subject: Re: CSI: Vanagon...Smog results!
> To: vanagon@GERRY.VANAGON.COM
>
> > Below you say to set the idle RPM to 950-1000. That happens to
> > be where my
> > van (84GL) passes. It does not pass at Bentley value of 650RPM.
> > What is
> > happening at 950-1000 that is not happening at 650RPM? Is it
> > just the heat
> > of the CAT or is there something else we should be considering?
> >
> > William
> >
> > On Wed, 31 Jan 2007 23:41:34 -0500, Dennis Haynes
> > wrote:
> >
> > >The crossover pipe on top of a giveaway. 1.9. The single pulley
> > indicates it
> > >most likely was a late '83 with the extremely early cooling
> > system and it
> > >may even have that odd ball 190 mm clutch and flywheel.
> > >
> > >Now for your emissions failure results.
> > >
> > >Your test is basically an idle speed and 2,500 rpm test. You
> > failure was
> > >both HC and O2. From a diagnostics point of view this is
> > extremely valuable.
> > >You r test results provide the justification for these testing
> > programs. You
> > >are a gross polluter putting out fumes like a Model T or a bad
> > lawnmower.>
> > >As a recap for the group, the test limits are 1.2% CO and 220
> > ppm HC. These
> > >are typical limits and all cat equipped vehicles should reach
> > it, even
> > >without a working cat. For information, the Dyno tests (IM 240)
> > is used to
> > >put the drive train under a sustained load to test for NOx
> > production. This
> > >tests the 3-way part of the cat, (CO, HC, NOx) and for engines
> > so equipped,
> > >the EGR function. Changes in ignition timing, gearing,
> > compression ratios,
> > >etc have adverse effects on NOx.
> > >
> > >Anyway, your results were 9.99% CO, 1700 ppm HC at idle and
> > 8.63% CO and 255
> > >ppm HC at 2,500 rpm. The O2% was .2 at 2,500 and 5.6 at idle.
> > >
> > >Normal atmosphere O2 is at least 19.5% these readings tell me
> > the thing is
> > >running real rich. There is obviously no O2 sensor control. The
> > fact that
> > >the HC drops at 2,500 rpm tells me there may also be an
> > ignition, timing or
> > >valve problem.
> > >
> > >First thing to do is test the O2 sensor. Put meter on it.
> > Measure between
> > >the sensor lead and a good chassis ground. With things cold,
> > when you first
> > >turn on the ignition, you should see ~.6 volts. The is the
> > leakage or bias
> > >voltage on the ECU amplifier input. A cold sensor is an open
> > circuit so you
> > >will see that. Now start the engine. As the sensor warms, you
> > may see the
> > >voltage drop but it should soon increase. Since you are so
> > rich, you should
> > >see close to 1.0 volt or maybe more. If not, sensor is shot.
> > >
> > >Next, after we know we have a good sensor, remove the cover
> > from the AFM.
> > >Disconnect the sensor from the ECU and connect it to the meter.
> > Start engine
> > >and watch voltage on sensor after it warms up. While engine is
> > running,>gently turn AFM wiper opposite the direction the
> > airflow is pushing it. The
> > >engine should lean out and the sensor voltage should drop.
> > Using the plastic
> > >wheel, tighten return spring to get the sensor reading to
> > around .5 volt.
> > >Rev the engine and see if you can get it close to that voltage
> > across the
> > >range. The idle bypass screw can help get the idle speed tuned
> > if needed. I
> > >usually just set it 2 turns open and a properly functioning
> > system will take
> > >it from there. Re-connect the sensor to the ECU. You should be
> > able to see
> > >the sensor reading vary from .2 to.8 volts. You now have O2
> > sensor control.
> > >If the throttle switch is working right, you can rev the engine
> > to say 1,800
> > >rpm, let go of the throttle, and see the O2 reading go to "0"
> > for a moment
> > >as the engine slows down. This is due to the fuel shut off when
> > the engine
> > >is above 1,300 rpm and the throttle is closed. Now, when the
> > fuel is
> > >resumed, the O2 sensor is ignored for 30 crank revolutions.
> > This is why the
> > >base mixture setting is critical. If the mixture is too rich
> > without the O2
> > >control, the engine will creep above the cut off speed, fuel is
> > shut off,
> > >the speed drops, and the cycle will continue. This is that
> > famed Digi-jet
> > >idle surge.
> > >
> > >For the basic settings, make sure the distributor vacuum
> > advance and retard
> > >are both working. Set the timing at the correct setting, over
> > advanced will
> > >increase HC at idle. Set warm idle high at 950-1,000 rpm. Makes
> > a big
> > >difference. Make sure the auxiliary air regulator is working,
> > getting 12
> > >volts and closing quickly. If the basics are set correctly, you
> > should no
> > >problem passing those limits.
> > >
> > >Dennis
>
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