<E30> I failed the NJ emissions test for NOx

[Gabriel Mintier <mintier@xxxxxxxxxxxxx>]

Dear List,

I waited until they rolled out the new Dynometer test before liscensing
my car after I moved here  -oops.  I now desperately seek the combined
knowledge of this list for any advice.  The car is a '90 325i with 107k
mi.  My results were:

SAFETY:	PASS
EMISSIONS:	FAIL

EMISSIONS RESULTS:
GAS	STANDARD	READING	RESULT
NOx	1110		4492		fail
HC	148		32		pass
CO%	0.83		0.24		pass
CO2%			14.2		
O2%			0.1		
RPM			0

Tabk Pessure	N/A
Gas Cap		pass
Purge			N/A
Tampering		pass
Visible Smoke	pass

My question is: where do NOx emissions come from?  I found one FAQ about
gasoline that said it was the product of atmospheric N2 and water or
oxygen, but it doesn't help me get to the cause.  I thought it could be
associated with a lean running condition but that is just a guess.  So
far I've only checked for major leaks of unmetered air.  I think that a
valve adjusment could help and one is probably due anyway.  Other things
I surmised after flipping through the bently manual are to check the air
mass sensor and the injectors and their seals.  Could it be the catylyst
even with the Carbon emissions low?  What about the O2 sensor?  It's
probably been 50k miles so I guess I should replace it anyway (oh
dread).  I just hope that someone might steer me in the right direction
before I start hap-hazardly replacing things like the injectors.

One thing I didn't catch at the testing place was that the RPM's on the
report say zero.  I guess they must have some bugs to work out with the
new system, I can't believe she would pollute like that without even
running!  I also started to think the problem was with how the guy
shifted the gears on the dynometer, or the atmospheric conditions that
day, but that's probably a long shot.

I'm running the stock chip.  Could the problem be inherent to the maps
for ignition and stuff?  I doubt that.  Last time I passed (in
California, after they recalled the dyno tests I think), 03/99, my
results were similar: at 2500 rpm (no load) HC=12ppm,  CO=0.1%,
CO2=12.8%, O2=3.1%, but no NOx read-out.

On second thought, maybe 0.1% o2 is too low.  I better go check the air
filter.  Maybe the car is lean for oxygen.  In any case I will keep you
guys informed. I hate to think that my car emits more than four times
the legal limit for some gas that causes acid rain, or, even worse,
hurting the performance or causing the engine to be eaten away by nitric acid.

For anyone in the Trenton or Princeton areas of New Jersey>
ANyone have any experience with BMW's Only (I think that's the name) of
Ewing?  Or any other independant BMW mechanics is the area?  I'm not
thrilled about going to the stealer, not only because of the $, but the
parts guy there was kind of rude to me.  What about the service at
Zygmut in Doylestown, PA?  Any help would be greatly appriciated.

Gabe M
BMWCCA #119061

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