Date: Mon, 17 Aug 2009 12:39:29 -0700
Reply-To: Rocket J Squirrel <camping.elliott@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Rocket J Squirrel <camping.elliott@GMAIL.COM>
Subject: Re: Not quite a backfire . . .
In-Reply-To: <002001ca1f69$a49bc6e0$6501a8c0@PROSPERITY>
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On 8/17/2009 11:36 AM Scott Daniel - Turbovans wrote:
> The coolant temp should not drop to a very low reading during a long
> descent in the summer.
> I would be thinking about a thermostat not working correctly if I saw
> that on one of my vans.
> This is the main thing I wanted to comment on.
With no pressure on the gas pedal, the fuel is totally shut off, so the
engine is not firing on any cylinders and after about 20 minutes with cool
air blowing past it, it will lose heat. I first observed this in 2007/2008
on the long drop down from Laguna Mountain in San Diego county and there
was quite a lot of to and fro on this matter until the list sorted this
out as being basically an off engine in cold air being spun by its
crankshaft. This is the second thermostat, and the behavior is the same.
It was probably in the low-50's outside, and that's cool enough to suck
heat out of the engine quickly. The Laguna Mountain descents were in the
30's and lasted 20 or 30 minutes. I don't think an engine can stay warm
with no fuel when driving @ 40 mph and spinning at 2,000 to 3,000 rpm very
long.
Where does the thermal sensor for the dash gauge sit w/r/t the thermostat?
engine side or rad side? Gotta be the engine side -- right?
> re
> With no fuel in the cylinders for so long, a
>> plug got fouled with oil. Unburned fuel got into the exhaust manifold and
>> ignited there, causing the mild explosions we heard.
>
> Yes....backfire like sounds can be from fuel in the exhaust system
> getting ignited.
> however, by your own logic and indications observed ( 02 meter ) you
> believe that the throttle switch shut off all fuel to the injectors,
> so how could there be unburned fuel in the exhaust system, if that were
> true ?
>
Ya didn't read my post well enough. When we hit the flat Mrs Squirrel
pressed lightly on the gas pedal, which would start gas going into the
intake. Any cylinder with a fouled plug, due to long downhill @ 2,000 to
3,000 rpm and no gas, would send that unburned fuel into the exhaust
manifold. To go "cough" as it popped out there.
> that sure is a special area.
> They only just opened McKenzie Pass *now* ?? In August ?
It's true -- they were re-paving it and now they are re-striping it.
I am certain that the re-paving was needed due to a$$holes like that Jack
Elliott fellow driving inappropriate vehicles over the pass. See
http://socal2bend.blogspot.com/2008/08/massive-trucks-migrate-to-eugene.html
> on the Eugene ( west ) side of the pass, about a mile or so from the
> pass itself, on the north side of the road, is a delightful small lake
> with some campsites around it. Always wanted to camp there once.
> There is also in that area, another *really* nice little lake, with
> free unrestricted camping, with campsites around the lake.
Yes sir, I agree. I gotta get me some Forest Service maps pronto -- the
area is peppered with intriguing places to camp. Right now, being stuck in
a wheelchair, I gotta stick to more developed places. Which suck, but we
gotta work with the present conditions.
--
Mike (aka "Jack" Elliott)
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
Bend, OR
KG6RCR
