There is some true to this. CO is generly formed form incomplet
combustion which is usually the the result or occurs durring lower
combustion temps which reduces NOx formation. As you raise peak
combustion temps and pressure you generally increase NOx as well so it
is a bit of a balancing act. EGR reduces peak temps and NOx too.
Excessive CO can be caused by other things as well. Over fueling is
not the lone cause. Basically it is from incomplete combustion and
there can be several causes for that with excessive fuel being but one
Not really. CO is because it is on completly burned properly not just
becuse the A/F ratio was wrong
It could be timing, low compression, bad EGR valve, plugs fouling,
low compression resulting in a poor burn, higher oil consumption which
slows burn and can add CO to name a few on top of a over rich mixture
and a overly lean one which can cause higher CO too. The fact the NOx
is low shows the combustion temps are low and likey not burning
properly since NOx is a direct result of combustion temps and
Horse droppings. CO increase is documented as being caused by
insufficient air for the amount of fuel.
Indirect cause. (if even that)
Sure, if it raises manifold pressure enough to cause power
enrichment, IOWs an indirect cause.
Nope. CO drops when a plug miss fires. No fire, no CO.
Motor oil falls into the 'over fueled' category.
Naming them doesn't make it true.
Not on this planet.
A company with the resources of say Toyota would certainly know
more about it than you;
The charts on pages 1 and 2 clearly show how air fuel ratio
effects CO levels. Page 4 shows likely causes of excessive CO,
notice how most of your so called causes for the high CO aren't
Note, the charts on pages 1 and 2 are pretty much an industry
standard and have been for quite a long time. They'd be found in
the documentation that comes with most if not all 2, 3, 4 and 5
gas analyzers, they are found in training materials from GM,
Ford, Chrysler and of course Toyota. They are acknowledged and
used in the emissions testing industry by the vendors who conduct
the tests and as part of their technician outreach programs.
And finally, there is a man named Brettschneider who says you are
full of shidt.
Without knowing what the pre-cat NOx levels are, you are just
YOur real lack of knowledge really shows through here as you suggest
that rich fuel mixtures are the only cause of this problem. Granted it
can be a cause but far from the only cause!
I love this, again your lack of wisdom and understanding on this
subject is shining through!
Agian you are so clueless because low or unbalnce compress can cause
incomplete buns and you would know that if you had any real knowledge
on the matter.
Again wrong on your concept. If there is enough EGR to delute incoming
mixture regardless of manifold pressure it will remove availble oxygen
for mixture and result in higher CO emissions.
I love this one, the unburnt fuel just disappears and does not
partically afterburn in exhaust huh. Again you lack of knowledge shins
bright like a beacon
The malarky her is you as usual
Trying to CYA on over rich huh? Not realy because though it is a fuel
it has different octane and burning properties so it is no lumped in
with "over fueled"
You mean you discounting them does not make them true right? YOu
should not be giving advise on things you do not understand ALL
Your realy are clueless huh? A overlean mixture will not burn properly
and BTW a over rich will also generally show high HC's as well while a
normal mixture that has high CO for some of the other reasons I
mentioned may have normal of near normal HC's
Post all the links you want it just shows that you really do not know
and you look stuff up when you are in a bind.
Again you are complete wrong to assume that over rich is the only
cause of high CO. it is but one cause and all of the tests you quote
are likely on perfect engines in lab conditions not realworld ones
with wear and age on them that are no longer up to full spec.
No, I am not guessing, you are. The CAT removes a percentage on them
not a fixed amount and the low reading clearly shows that combustion
temps are likely low because as stated earlier that has a direct
bearing on NOx production which you would know if you really had a
Blojob, you are right on every point. Everyone but you is clueless
and makes guesses in place of factual statements. I think they act
this way to feel better about themselves. Keep up the quality,
factual info. Your input is appreciated here. Heck, I search for
your posts every day now. Thanks for pointing out that some of our
best mechanics in the repair industry are really just ignorant frauds.
Toyota MDT in MO
Love anything you want, still doesn't change the facts.
That would produce a miss fire and there would be high HC as
Concept? It's proven science.
On MAF engines, EGR does NOT change the air fuel ratio, on speed
density engines, the EGR changes the air fuel ratio because it
directly effects the manifold pressure and the device reading it.
EGR "removes available oxygen?" Pure Snojob magic.
Any *professional* mechanic can access the writings of Paul
Baltusis (Ford Motor Company) and Robert Schrader (Bridge
Analyzers) and find that you are 100% wrong.
Unburned fuel shows up as HC, not CO.
BTW, fuel is not "burnt" it is 'burned'
(as if we needed yet another example of your intellectual prowess)
Why would a slow burn add CO?
Nope, just showing where you are wrong.
It certainly is.
And you -do- understand all aspects? I find that hard to believe
given the number of and history of making grand blunders you are
Results in high HC and lowered CO.
Grossly over rich will show high HC in addition to high CO.
"Normal mixture that has high CO?" What sort of nonsense is that?
And they said the Dinosaurs were extinct.
It's called a reference that supports what I've been saying you
Too bad, tough shit, you lose.
If I am completely wrong, so is the entire automobile industry
along with all of the manufacturers of support and diagnostic
equipment, the states of Arizona, Ohio, New York, Pennsylvania,
Colorado, Wisconsin and California being as those are the states
I worked with 11 years ago when I was employed by the worlds
largest emissions testing company. But you know, I just can;t
see the ranting of one little bozo with a snow plow trumping all
of those highly educated people.
It's basic combustion chemistry you dolt. Matters not how worn
How can you NOT be guessing if you are NOT testing?
Uh-huh... High CO and low NOx are never EVER caused by over
fueling, even though that is exactly what is shown in the 4 gas
chart referenced earlier, i.e., on the rich side of
stoichiometric. Apparently you would rather ignore the evidence
as presented and guess at the cause, which pretty much proves
that any test results over and above hitting something with a
hammer is totally lost on you.
No wonder you can't get your truck to run correctly unless you
jack the adjustments. (which is a whole different subject of
Thanks for all the ideas - I should mention that despite these readings this
S10 starts up in zero degree weather in less then a 3 second crank which is
why I like to keep it around for winter driving - so I always thoguht that
it was properly tuned....
I've stayed away from this post until now because I'm not a professional
mechanic, nor do I own an S10, therefore I don't know how to tune your
engine and I thought someone with more experience would point you in
the right direction - which I think the over fueling remark was meant as.
It's my understanding that the NOx and CO emission from an IC engine
are inversely proportional, that is, as you tune the engine to reduce NOx,
the CO will increase and vise-a-versa. I also noticed from your OP that
while the CO is slightly over limit, the NOx is much below the limit.
Therefore, I would start with a basic tune-up including:
Adjust fuel/air ratio.
Replace the air cleaner.
Inspect and if necessary, replace the distributor cap and rotor.
If you replace the distributor cap, replace the spark plug wires.
Inspect and if necessary, replace the spark plugs.
You didn't mention how many miles are on your '85, or how long its been
since your last tune-up, but, replacing the above mentioned components
can't hurt (except maybe your wallet) ;*)
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