Date: Tue, 15 Aug 2006 11:23:02 -0700
Reply-To: Stephen DeMocko <SDeMocko@FDSMFG.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Stephen DeMocko <SDeMocko@FDSMFG.COM>
Subject: Re: Desperately Need Smog Help...Read all past posts....
Content-Type: text/plain; charset="us-ascii"
Volks,
I failed a smog check recently with a new rebuild, a hot engine, and an
oil change. I had been waiting for this to happen before I installed the
new cat I had, and decided to put in a new O2 sensor. I have to say
that even after doing this I noticed very little change in idle or power
but look at how much the numbers changed
Before:
CO2(%) O2(%) HC(ppm) CO(%) NO(ppm)
Test RPM MEAS MEAS Max Ave Meas Max Ave Meas Max Ave
Meas
15mph 2094 14.00 .57 131 43 86 .87 .16 .91 1085 406
1719
25mph 1997 13.49 1.02 103 32 91 1.10 .15 .95 1120 349
1176
After:
CO2(%) O2(%) HC(ppm) CO(%) NO(ppm)
Test RPM MEAS MEAS Max Ave Meas Max Ave Meas Max Ave
Meas
15mph 2029 15.00 .09 131 43 24 .87 .16 .05 1085 406
72
25mph 1998 15.00 .03 103 32 21 1.10 .15 .09 1120 349
71
Stephen DeMocko
('85 Westy Luci)
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of Dennis Haynes
Sent: Tuesday, August 15, 2006 10:40 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Desperately Need Smog Help...Read all past posts....
Over advancing the ignition timing is the worst thing to do for
excessive HC at idle. This causes insuffecient airflow so HC and CO will
sky rocket. You need to find the real problem. If it is a low mileage
rebuild, a compression and leak down test should be performed both to
get a base line and valve problems are plentiful on new heads. After
confirmation, of sound engine, next thing to check is the ignition
system, particularly the wires. The resistor ends do go bad. The next
step is injecter condition, matched output and good spray pattern. you
don't say what the CO is. This will tell if the O2 sensor is trying to
work. A new sensor does not mean the wiring and controller is right.
Make sure the engine is not overfilled with oil. This can add to the HC
readings although you are so far out there. If all is well, HC should be
under 100 before the Cat with CO ~.5%. After a really good Cat, you
should see near 0.
Dennis
----- Original Message -----
From: Anthony Rutland
Date: Tuesday, August 15, 2006 12:55 pm
Subject: Desperately Need Smog Help...Read all past posts....
To: vanagon@GERRY.VANAGON.COM
> Hello all,
>
> New to this list but been on the syncro vanagon list for a
> long time. A friend reccomended I pose my smog challenge to the
> gurus here.
>
> 87 VW vanagon syncro. Just installed an AVP rebuilt motor with
> 37K on it from a subie'd vanagon. Runs great and passes smog at
> anything other than an idle.
>
> Currently at idle it runs rough. Like it has a miss. I have
> done the brakleen vaccum test at every junction. Contact cleaned
> all electrical connections and grounds. Different AFM's, Idle
> control module, Idle control vavle hums just like it should.
> Even tried different computers. I have a Bosch D and a Triumph
> Allen. Runs better on the bosch which is stock for my van.
> Replaced two injectors as the tips looked scorched.
>
> First test was gross polluter on all counts. New cat and it
> was a GP at idle with 777 measured on HC. Passed everywhere else.
>
> Full tune up, plugs, wires, cap, rotor, O2 sensor, temp II
> sensor. Still failed at idle this morning excpet this time it
> was 800 HC at idle.
>
> Lastnight my neighbor Craig Forney came over and took a look
> at it. We bumped up the timing just barely as it was falling
> flat on its face at the stock setting. We also turned in the
> throttle body air bypass screw (affects idle) 4 full turns.
> Otherwise the idle was going too high with the timing just
> slightly advanced. Could this affect the smog readings adversely?
>
> So thats where I am at currently. Any thoughts, expertise and
> advice greatly appreciated. Shops are expensive to troubleshoot
> these problems here in the California bay area.
>
> Anthony
>
>
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