[V8] Re: V8 smog blues

Buchholz, Steven Steven.Buchholz at kla-tencor.com
Wed Apr 21 17:28:54 EDT 2004

... thanks to all of you who have offered suggestions on and off list!
Funny, with me being as busy as I am I often forget to mention some of the
other things I had intended to note in my initial message ...

One thing I noticed was that while the test was going on the engine RPMs
were varying noticeably, perhaps 100 RPM peak to peak.  I don't know if the
tech was messing with the throttle while he was running the test, trying to
hold the idle steady ... or perhaps trying to increase the emissions ... he
didn't try to get me to pay him to fix it, so I don't think he was
deliberately trying to make it fail ... nonetheless I find that when I try
to hold steady 2500 RPM I can do so just fine from the handle on the
throttle body.  Perhaps this was just enough variability to put the car over
the maximum ... 

Since the car has permanent AWD it was not forced to sit on the dyno, so the
dynamics of how quickly the engine was throttled ... or whether or not the
car has a manual tranny don't apply.  

... as to the comment about the second car ... even though this is the car
with the "new" engine, I actually am a bit concerned as to whether or not it
will pass.  Where a whiff of the exhaust on #344 gives no obvious
hydrocarbon smell, I can tell that #2 is running rich for some reason.  I
suppose I should figure it out because it is rich enough to noticeably
affect fuel economy ... that said, I have been considering whether or not it
makes sense to try swapping things like injectors ... but since the car is
close to passing, I'm hoping that some less expensive approaches will do the
trick ... not that a set of plug wires are that cheap!

... the comment about heating up the cats might be a good one, but I am a
bit skeptical because the standard process is that if the emissions fail on
the initial attempt the program runs the car at 2500 RPM for 3 minutes
before retesting ... 

> I have heard it said before on this list that during the 
> test, bring it
> up to RPMs slowly, and drop them slowly...  Doing it to quickly causes
> it to belch environmental obscenities.
> Here in Portland, they have to do the sniffer test (as our DEQ doesn't
> have an AWD dyno) and they have the owner do the stepping on the gas.
> If you are close to passing, this might help.
> If only Steven had a second car he could swap parts off of... ;-)
> You might want to take the V8 out for a spin on the highway 
> to make sure
> the cats are fully up to temp.  I have heard of this helping.

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