Away we go again. Dan, why do you suddenly cross post this BS without
giving us the full post you are replying to?

It makes you seem like a total ass and yet you do it all the time.

The last couple times folks have asked for clarification, you have
ignored it.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

"Daniel J. Stern" wrote:
>
> On Fri, 27 May 2005, Mr. Minnow wrote:
>
> > I took my car(87 5th Ave with a 318(5.2L) v8) in for an emission test and it
> > failed miserably
> >
> > Here are the results:
>
> It's *very* hard to read your results -- the tabulation didn't come out as
> you tried to make it do -- but it looks to me as if your results a
>
> HC: 197ppm (limit 83ppm, FAIL)
> CO: 0.16% (limit 0.46%, PASS)
> NOx: 1220ppm (limit 893ppm, FAIL)
>
> Your CO is about 1/3 of the allowable limit, and is an excellent reading
> for a carbureted car -- but your HCs are more than double the allowed
> limit, and your NOx is 1/3 higher than allowed. This combination of
> results suggests your engine is running so lean that it is misfiring.
> Those cylinders that do fire produce a great deal of NOx due to the lean
> mixture, while those that do not fire produce a great deal of HC due to
> noncombustion.
>
> (These '85-'89 civilian M-body cars with the Holley 2bbl don't generally
> run very well in stock form, even when everything is set by the book. Lean
> surge under steady throttle is the rule, rather than the exception. Not
> that this helps you -- just saying.)
>
> So, what's causing your misfiring? Could be any number of things. A faulty
> Oxygen sensor in the driver side exhaust manifold (how long since you
> replaced it?). A faulty carburetor, a faulty Lean Burn computer, a plugged
> fuel filter...it might not even be a lean misfire at all; your readings
> could also be caused by the reduction portion of the exhaust catalyst
> system having reached the end of its life, resulting in very high NOx
> tailpipe readings and insufficient free Oxygen in the exhaust stream to
> allow the oxidation section of the catalyst to clean up the HC.
>
> Time for some systematic diagnosis by someone who has considerable
> experience with the carbureted Mopars of the mid '70s through late '80s.
> Just throwing parts at it will get very expensive long before the problem
> is solved.
>
> DS