Date: Sun, 12 Jun 2011 23:02:32 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: The Dreaded Emissions test
In-Reply-To: <BANLkTik-MbN45Cpx9d-wAzVTUBs3ug9D+g@mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"
NOx emissions are the result of heat, pressure, and excess O2. As such
testing requires the engine to be loaded. That is why some areas use the
dyno as this is the only way to test for NOx emissions. Now for CO and HC
here is some diagnostic information.
CO (carbon monoxide) is the result of incomplete combustion due to O2 not
being combining with the fuel, usually caused by a rich mixture or poor
vaporization and mixing.
Excessive HC (hydrocarbons) is the result of fuel that never got ignited or
escaped before the burn was complete. Although with good ignition and
mixture the burn should finish in the catalytic converter or exhaust. This
is why many cars have air pumps or other means to get air into the exhaust.
The usual causes of high HC are "lean Misfire", bad valves, pistons,
ignition miss, or ignition timing way off.
If your van does not have an O2 sensor for final control you should be
adjusted somewhere near 1% pre cat at idle.
With the engine being fairly new I have to ask if it was tested as part of
the installation? Has the engine operation changed at all? Maybe it wasn't
right from the get go. The high idle is a sign things were not set up
correctly.
As part of the trouble shooting process and to make sure the engine is good
you need to get a compression and leak down test performed. These engines
are known for valve and head seal issues. The heads not sealing to the
cylinders are often the result of the cases being worn or distorted.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Ken Wyatt
Sent: Sunday, June 12, 2011 12:26 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: The Dreaded Emissions test
Opps sorry I somehow deleted the results of the second test on a very
warm engine. It still failed after freeway driving. HC was still
over the max of 220 at 437 PPM versus 469 PPM cold. CO was 2.83% cold
and 1.577% warm. The CO2 on the first test was 12.94% and O2% was
1.46% at 2500 RPM. At Idle it was CO2 at 11.37% and O2 at 2.07 %. It
appears we don't check NOx anymore here in Salt Lake.
I had always heard that the older VW aircooled engines were designed
to run slightly rich to enhance engine cooling. Anyone care to
comment on that. My mechanic is an old VW guy from way back and I
feel he knows the engines. He completely built it last year with new
heads and all. So i am having him take the first look at it this week
while I'm working, hoping its just a small adjustment. Will report
back.
Cheers,
Ken Wyatt
82 westy
Thinking of mounting my 1976 Lincoln Continental Mark IV's large
chrome grill onto my 82 Westy, as soon as I add a radiator for the
460. It fits the front vanagon contours well.
On Fri, Jun 10, 2011 at 12:42 PM, Ken Wyatt <57skibum@gmail.com> wrote:
> Howdy vanagonauts, I'm having trouble getting my 1982 westy to pass
> Utah emissions. Scary thing is that it has a new (3000 miles)
> aircooled 2.0 l FI engine. I thought it would be no problem to pass.
> But NOT!! I'm failing on the idle HC and CO.
>
> Last Friday for the first try, the mechanic tested the engine cold and
> got HC at 469 (passing is 220 or less), and 2.83 on CO (passing is
> 1.2% or less) The higher 2500 RPM test resulted in HC 203 and CO at
> 0.979 % which was passing just barely passing there.
>
> I figured that it was just the cold engine. So today I drove it until
> it was completely at operating temp quick thoughts on where to start
> or what to check? The engine sounds perfectly VW to me. The idle is
> running about 1100 and I'm wondering if that's slightly high.
>
> It sure would be nice to go camping but no registration.............. No
fun!!
> Ken Wyatt
> 82 westy
>