Date: Thu, 7 Feb 2008 15:55:06 -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: SMOG TEST failure
In-Reply-To: <47AB86A5.807@ucsb.edu>
Content-Type: text/plain; charset=ISO-8859-1
Scott Daniel offers some very valid areas to check.
My experience with high HC (Hydrocarbon) readings usually stem with "old"
oil or that an oil change hasn't happened within the past couple of thousand
miles.
Anytime I get my VWs ready for the dreaded California Smog Test I do the
following the day or two before:
*Oil & Filter Change
*New Spark Plugs (Wires too if they're old)
*New Rotor
*New Cap
*Check & adjust the timing to specs
*Replace the O2 Sensor (they're cheep enough, even if they're under the 50K
replacement suggestion).
On the day of the test, just before taking it in, I usually head out onto
the open highway to "wind" it out and get it nice and fully warmed up, then
drive it over to the inspection station.
Generally, I pass everytime I do the above.
If the Catalytic Converter has been on for a LONG time or the mileage is
unknown, I usually bite the bullet and replace it as well, but YMMV.
Usually, the AirBox/AFM doesn't need fiddling with, especially if it hasn't
been messed with by the previous owner. This is sometimes hard to
determine. On my Westy, the original was so wasted from over the years
useage that I replaced it with a Python Reman, had a shop with the proper
analyzing probe tool check the exhaust and adjust the volume screw once -
and that was 8 years ago. Haven't had to fiddle with it since.
Both my Vans are Digijet and so the Idle Stabilizer system is different, so
I'm not as familiar with the Digifant system, but from your description it
sounds like it's operating within nominal specs, but I could be wrong.
Hope this helps
--
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 Feb 7, 2008 2:31 PM, John Goubeaux <john@ucsb.edu> wrote:
> My 90 failed the California smog test today. In short, the idle values
> were off with HC ppm at 424 where max allowed is 120 though the 2500rpm
> values passed fine and are way below limits.
>
> So I am looking for some clues on where to start with this, and while I
> realize it might not be straight fwd, thought I would see if anyone has
> some insights. Replacing components one by one might get expensive so i
> was hoping on narrowing it down on what it **could be.
>
> Idle is fine though it has been rough for a while at startup and I have
> had intermittent, what appears like missing at high speeds when
> accelerating. I had thought that i was seeing what folks refer to as
> the "vanagon syndrome" but with with the idle values like these am
> thinking that it could be as a result of the idle control valve (though
> it vibrates), the idle control unit or the coolant temp sensor (which i
> am told can cause a rich mixture.
>
> It looks like Bentley has clear steps to trbl shoot the idle though I am
> not sure, without the proper tools, if I can make the needed adjustments
> it calls for.
>
> Thanks in advance for any wisdom that can be shared..!!
>
> -john
