Date: Wed, 7 Oct 1998 23:01:23 -0400
Reply-To: EMZ <vw4x4@FYI.NET>
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: EMZ <vw4x4@FYI.NET>
Subject: Re: Emissions Testing, passed! (third time's a charm)
In-Reply-To: <19981007.194156.9983.0.kdlewis@juno.com>
Content-Type: TEXT/PLAIN; charset=US-ASCII
my guess would be getting the motor hot by dirving
around. This is the munber 1 cause of failure!
Eric 86-VW4x4
vw4x4@fyi.net 72-240z
Pittsburgh, PA USA 1936-Chrysler
On Wed, 7 Oct 1998, kenneth d lewis wrote:
> Greetings and Salutations;
> Here is a brief synopsis of actions I took to get my truck to pass. I did
> not use any stop-gap solutions but strove to pass legally.
> -------------------------------------------------------
> First testing:
> Reading Standard
> Hydrocarbons (ppm) 266 ppm 220ppm
> Carbon monoxide(%) 0.40 1.2
> Carbon dioxide(%) 11.8
> Engine RPM at reading 894
> --------------------------------------------------------
> Where upon I proceeded to:
> 1> poll the list for suggestions.
> 2> changed the oil.
> 3> Set the timing properly. I had it slightly advanced to improve
> performance.*
> 4> Checked compression(125,125,125,139). Noticed #4 plug looked
> wet,appeared to be a small amount of oil.
> 5>Attempted AFM calibration using O2 sensor and adjusting spring. I
> felt positive results were achieved.
> 6>Ran a tankful of gas with Injector cleaner through.
> 7>Drove for 15 minutes at 65+mph to testing station to warm up
> engine.
> Second test(about a month after first) the readings were about the same!
> HC still failed.
> Back to the drawing board.
>
> A> Purchased K&N air filter.
> B> Replaced both fuel filters.
> C> Fuel rail hoses looked bad so they were replaced.
> D> Switched to Platinum plugs. Reasoning here was better firing if #4
> was oil fouling.
> E> Set idle stop as per Bentley.
> E(1)> Re-did AFM calibration.
> F> Reset idle. Ended up turning Idle Set screw almost all the way
> in. This took several turns. Made up the balance of idle air
> with the Air Bypass Valve(aka idle stabilizer valve)
> adjustment.**
> F(1)Test ABVs current as per Bentely=430mv.
> G> Drove around for about 40 minutes before testing.
> H> Went to a different tester.
> I> First customer of the day so I was tested immediately after
> machine's daily calibration.
> -------------------------------------------------------
> Third testing:
> Reading Standard
> Hydrocarbons (ppm) 99 ppm 220ppm
> Carbon monoxide(%) 0.04 1.2
> Carbon dioxide(%) 7.9
> Engine RPM at reading 883
> --------------------------------------------------------
>
> HC was less than half and CO2 improved by a factor of 10!! I wish I could
> point to a single action that did the most good.
>
> *The performance now, with near factory settings, seems as good as ever.
> **I do not recommend "experimenting" with this adjustment, I think that
> is what fouled things up. Right before this I had a very rough cold idle.
> My theory is the engine has two sources for it's idle air. The throttle
> body and the ABV. I believe this ratio got way off. I still had the
> correct volume for good hot idle but there was insufficient going through
> the ABV to modulate a good cold idle. There is no procedure in the
> Bentley, I learned about it on the list and fooled with it to try and fix
> a problem several months ago.
>
> Drive Safely & Good Luck
> Ken Lewis<Kernersville,NC>86 VW crewcab;60 T-5 Coupe
>
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