Date: Mon, 17 Aug 2009 10:10:43 -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: Not quite a backfire . . .
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Mrs Squirrel got a hankering to pick some blueberries yesterday, so we
took a trip over the Cascades Mountains from Bend, Oregon, down towards
Leaburg (on highway 126) to find some. For the view, we drove over the
McKenzie Pass-Santiam Pass Scenic Byway (highway 242, the Old McKenzie
Highway), which has just opened. It's an amazing road, crossing and
running next to old lava flows -- stop at the top for a cool view
(http://vulcan.wr.usgs.gov/Volcanoes/Oregon/HighCascades/dee_wright_observatory.html).
After topping the pass, we got stuck behind a line of cars for about 45
minutes until a flagman let us through -- ODOT was striping the new
pavement and we had to wait until the paint dried in the cool temps before
they'd let us down the other side.
Watched a mess of small orange butterflies on the black lava rocks warm up
their wings in the sun and take short test fluttersby for the duration.
When the flagman eventually released us we drove down the steady, winding,
hair-pinny downhill cruise of about 20 minutes. Mrs Squirrel rarely
touched the gas pedal. The auto tranny (84 Vanagon) was in 2nd, the engine
rpm-ing at about 3,000 so as to save the brakes; the smell of scorched
brakes from cars ahead of us suffused the morning air.
Mmmm . . . hot brake pads.
I know from previous long descents in cold temps that when there is no
pressure on the accelerator pedal, a switch on the throttle body tells the
ECU to shut off fuel, and the only source of heat for the engine is
friction resulting from being driven by the transmission. As expected, the
temp gauge dropped to nearly dead cold. The O2 meter showed pure lean
mixture: air, in other words.
Midway down we hit a flat stretch of road about a half mile long and Mrs
Squirrel pressed on the gas pedal a bit as the van slowed and said that
nothing was happening, no engine power. There were a few mild coughs from
the engine compartment. Not loud enough to be backfires, I don't know what
those coughs are called, they were new to me.
I suggested she press a bit harder, and the engine sped up, a bit
reluctantly, and sounded like it was missing on one cylinder.
HERE'S MY GUESS ABOUT THAT: 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.
When the road began to drop again, the foot came off the gas again and
fuel turned off, and the engine continued cold. A bit later we were at the
junction with the main highway. A left turn. Look left, look right, look
left again then a press on the accelerator to get up to speed and from
that moment on, the engine behaved quite normally. Temp rose up to normal
range and full "power" (if that is the correct term for what a 1.9l
provides) was available.
So everything appears to be fine.
--
Mike "Rocket J Squirrel" Elliott
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
Bend, OR
KG6RCR