Black "soot" from tailpipe. What is causing this???
Robert McElwee
do to fix this?
Miata Guy
"Robert McElwee" <rmce...@mymiata.com> wrote in message
news:e_9m5.1254$z64.2...@den-news1.rmi.net...
EricZieglr
>My bumper (I have a white car) is always black from my tailpipe.
Unless your bumper is showing a LARGE area of soot, it appears to be a normal
condition. I bought my white '99 new, and every time I wash it I find a small
build-up of blackness around and on the pipe.
Eric Ziegler
Amy Miller
rmce...@mymiata.com wrote on 8/15/00 6:46 AM:
> My bumper (I have a white car) is always black from my tailpipe. What can I
> do to fix this?
>
>
Probably due to impurities in the gasoline (carbon, point of fact). No
gasoline is perfectly perfect but if you are getting the cheapest gas you
can, it might do your system some good to bump up to a good brand (Texaco
comes to mind). You might also try some gas additive system cleaner to get
rid of any built up gunk as well. There will always be a little and if you
wanted to really get rid of the problem, you could get a slightly longer
tailpipe :-)
Amy and Seeger
'91 Silverstone "A"
"The horizon is nothing save the limit of our sight."
--
BRUCE HASKIN
Terry is the only one to even come close to helping you out. He should
have added "Hotter" spark plugs to his list.
My '91 runs so clean, you can wipe the inside of the tail pipe with a
white rag (anytime after it has been run on the road) & only see a
slight trace of black.
When I autocross it, I use 92 oct. & it will soot more, but that is a
lot of full on the gas that does that & 92 oct. burns slower.
If you have that much "soot" , you need to get it looked at. It's rich
& not all the gas is burning in the engine. It's trying to burn in the
exhaust system too.
Bruce RED '91
Terry & Chris Obeney
engine is running too rich (too high gas-to-air ratio). Even during warm-up
it shouldn't show up. If you have an excessively heavy right foot the
mixture will peak rich during hard acceleration bursts but even that is
marginal. I'd check your engine temperature sensor. A faulty sensor could
feed a low temp signal to the computer which which enrich the mixture even
though the engine is hot. This will cause the condition and will overcome
the corrections fed back to the computer from the oxygen sensor. Just a
possibility. Good luck
Robert McElwee <rmce...@mymiata.com> wrote in message
news:e_9m5.1254$z64.2...@den-news1.rmi.net...
T. Kennelly
address this problem?
Robert McElwee
blech-wite. They work the best but it is still permenantly stained.
"Miata Guy" <mx5_mi...@hotmail.com> wrote in message
news:Slam5.10415$T9.17...@news0.telusplanet.net...
> Wash, rinse, repeat...
Marty Harrison
> My bumper (I have a white car) is always black from my tailpipe. What can
I
> do to fix this?
>
removing surface impurities from new and old paint. Perhaps once you solve
the problem of why the soot is building up, you can get rid of it with clay
magic and a little elbow grease!
Regards,
Marty
'94 Laguna Blue
Scott L. Liechti
Glenn Price
degrees using 92 octane and the problem didn't change at all.
Glenn Price
T. Kennelly <tken...@cfl.rr.com> wrote in message
news:3999FEB1...@cfl.rr.com...
Glenn Price
worry, your bumper isn't permanently stained, I had the same problem and the
bumper came completely clean after using the stuff above.
Glenn Price
Robert McElwee <rmce...@mymiata.com> wrote in message
news:qKvm5.1520$z64.2...@den-news1.rmi.net...
> Only one problem - the stuff doesn't wash off. I use rubbing alcohol or
> blech-wite. They work the best but it is still permenantly stained.
>
> "Miata Guy" <mx5_mi...@hotmail.com> wrote in message
> news:Slam5.10415$T9.17...@news0.telusplanet.net...
> > Wash, rinse, repeat...
> >
vinnie
In article <ymBm5.10984$4T.6...@bgtnsc07-news.ops.worldnet.att.net>,
"Glenn Price" <nospammin...@worldnet.att.net> wrote:
> You can get the stuff off with either rubbing compound or degreaser...don't
> worry, your bumper isn't permanently stained, I had the same problem and the
> bumper came completely clean after using the stuff above.
>
> Glenn Price
>
--
****delete "blah" to reply****
Leon van Dommelen
>You can get the stuff off with either rubbing compound or degreaser
I had a Genie exhaust (which has too short a tail pipe) on a Sebring Miata
(which runs rich on feathering the throttle) and had this *bad*. I used bug
and tar remover. I may note that it appeared the soot was hard to
get off because it seems to get stuck in the wax. In other words,
I believed I was solidly dewaxing the area to get it clean. (Which WD-40
should also do well; I did not try.)
>...don't
>worry, your bumper isn't permanently stained, I had the same problem and the
>bumper came completely clean after using the stuff above.
Same here. Bumper was completely unaffected.
Leon
--
Leon van Dommelen :) Bozo, the White 96 Sebring Miata .)
Our last trip at http://www.dommelen.net/miata/tripsu00
REMOVE THE "z"s -> domm...@zmiata.net www.dommelen.net
T. Kennelly
Since you were running 18 degrees of advance AND 92 octane do you support the high octane had an effect on the
temperature of the combustion (before the exhaust valve opens)
Speculation off.
Glenn Price wrote:
> I had this same problem, with timing at 10 degrees, and up the timing to 18
> degrees using 92 octane and the problem didn't change at all.
>
> Glenn Price
>
> T. Kennelly <tken...@cfl.rr.com> wrote in message
> news:3999FEB1...@cfl.rr.com...
Glenn Price
increasing temperature, and 92 octane fuel burns hotter so that's a double
whammy. If I had not run 92 but increased the advance like I did, I'd get
higher temps anyway and probably a couple holes in my pistons too! :)
Glenn Price
T. Kennelly <tken...@cfl.rr.com> wrote in message
news:399BEBF9...@cfl.rr.com...
> Speculation on (i.e., this is just guess work on my part)
>
> Since you were running 18 degrees of advance AND 92 octane do you support
the high octane had an effect on the
> temperature of the combustion (before the exhaust valve opens)
>
> Speculation off.
>
> Glenn Price wrote:
>
> > I had this same problem, with timing at 10 degrees, and up the timing to
18
> > degrees using 92 octane and the problem didn't change at all.
> >
> > Glenn Price
> >
> > T. Kennelly <tken...@cfl.rr.com> wrote in message
> > news:3999FEB1...@cfl.rr.com...
Leon van Dommelen
>Yes, by increasing the timing advance the combustion pressure increases thus
>increasing temperature, and 92 octane fuel burns hotter
It does? How much?
> so that's a double
>whammy. If I had not run 92 but increased the advance like I did, I'd get
>higher temps anyway and probably a couple holes in my pistons too! :)
>
>Glenn Price
>
>T. Kennelly <tken...@cfl.rr.com> wrote in message
>news:399BEBF9...@cfl.rr.com...
>> Speculation on (i.e., this is just guess work on my part)
>>
>> Since you were running 18 degrees of advance AND 92 octane do you support
>the high octane had an effect on the
>> temperature of the combustion (before the exhaust valve opens)
>>
>> Speculation off.
>>
>> Glenn Price wrote:
>>
>> > I had this same problem, with timing at 10 degrees, and up the timing to
>18
>> > degrees using 92 octane and the problem didn't change at all.
>> >
>> > Glenn Price
>> >
>> > T. Kennelly <tken...@cfl.rr.com> wrote in message
>> > news:3999FEB1...@cfl.rr.com...
--
Leon van Dommelen
>not a problem at all.....original (European) mx-5's run and imported Miata's
>from the US or Canada run perfectly on the fuel here....it is at lest 95
>octane, and premium is 98 in the Netherlands,
The octane in Europe is computed differently than in the US. Don't know
or remember what the difference was, but you cannot simply compare numbers.
> and no one has problems with
>the "hotter burning"
Here is an earlier post indicating higher octane does not burn hotter:
|From: raw...@aol.com (Rawdomg)
|Subject: Re: Octane Rating?
|
|>Some engines actually have more deposit problems with a higher octane, since
|>it burns slightly cooler.
|
|I don't believe the flame temperature is significantly lower (absent profound
|knocking, that is). The increased deposits are generally due to higher amounts
|of condensed ring aromatic hydrocarbons in most premium gasolines compared to
|regular. And yes, I can provide a reference for this, Including the phone
|number of the researcher who published the technical paper.
> the higher octane just means it burns easier,
Actually, the higher octane means it starts burning *less* easily by itself
before the flame front hits it. (Less knock=autoignition)
>but not hotter.
The other post seems to agree with you. I have a vague memory that someone
might have posted a table of info on various fuels, but if true, I did not
save it.
>Regards Jasper
>
>Glenn Price wrote in message ...
>>Yes, by increasing the timing advance the combustion pressure increases
>thus
>>increasing temperature, and 92 octane fuel burns hotter so that's a double
>>whammy. If I had not run 92 but increased the advance like I did, I'd get
>>higher temps anyway and probably a couple holes in my pistons too! :)
>>
>>Glenn Price
>>
>>T. Kennelly <tken...@cfl.rr.com> wrote in message
>>news:399BEBF9...@cfl.rr.com...
>>> Speculation on (i.e., this is just guess work on my part)
>>>
>>> Since you were running 18 degrees of advance AND 92 octane do you support
>>the high octane had an effect on the
>>> temperature of the combustion (before the exhaust valve opens)
>>>
>>> Speculation off.
>>>
>>> Glenn Price wrote:
>>>
>>> > I had this same problem, with timing at 10 degrees, and up the timing
>to
>>18
>>> > degrees using 92 octane and the problem didn't change at all.
>>> >
>>> > Glenn Price
>>> >
>>> > T. Kennelly <tken...@cfl.rr.com> wrote in message
>>> > news:3999FEB1...@cfl.rr.com...
--
Leon van Dommelen :) Bozo, the White 96 Sebring Miata .)
REMOVE THE "z"s -> domm...@zmiata.net www.dommelen.net
"EXIT THE INTERSTATES" (Jamie Jensen)
DLynch
Without catalytic converters and other emission systems, unburnt
hydrocarbons and other pollutants would be released from your tailpipe.
Before emission control we expected to see light tan coloured exhaust tips
in well tuned cars.
Now we have emission controls that burn those hydrocarbons in the exhaust
system, and remove other pollutants too. The oxygen sensor is part of a
feedback loop. They work in a horrible (hot, very hot, and polluted)
environment. So they don't last.
If I noticed soot on my tailpipe I'd get the car tuned. And I think that
oxygen sensors are covered by an 80,000 km emission warranty. So if the car
is young enough, it may be free.
Dave L.
Jasper Nap
from the US or Canada run perfectly on the fuel here....it is at lest 95
the "hotter burning" the higher octane just means it burns easier, but not
hotter.
Regards Jasper
Glenn Price wrote in message ...
>Yes, by increasing the timing advance the combustion pressure increases
thus
>increasing temperature, and 92 octane fuel burns hotter so that's a double
>whammy. If I had not run 92 but increased the advance like I did, I'd get
>higher temps anyway and probably a couple holes in my pistons too! :)
>
>Glenn Price
>
>T. Kennelly <tken...@cfl.rr.com> wrote in message
>news:399BEBF9...@cfl.rr.com...
>> Speculation on (i.e., this is just guess work on my part)
>>
>> Since you were running 18 degrees of advance AND 92 octane do you support
>the high octane had an effect on the
>> temperature of the combustion (before the exhaust valve opens)
>>
>> Speculation off.
>>
>> Glenn Price wrote:
>>
>> > I had this same problem, with timing at 10 degrees, and up the timing
to
>18
>> > degrees using 92 octane and the problem didn't change at all.
>> >
>> > Glenn Price
>> >
>> > T. Kennelly <tken...@cfl.rr.com> wrote in message
>> > news:3999FEB1...@cfl.rr.com...