Date:         Fri, 17 Aug 2012 11:48:19 -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:      Start-Stop Syndrome Returns
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Two years ago, while driving back from Flathead Lake in Montana, my van
got all weird on me. I posted the symptoms but no one was able to
provide a good idea of the cause.

Mrs Squirrel and I just returned from a ten-day camping trip in Eastern
Oregon and the problem re-occured. Rather than point back to the old
thread, I'll just describe what happens.

1984 1.9L auto transmission

SYMPTOM: When climbing up steep, long grades in hot (90F+) weather.
engine repeatedly cuts out for about five seconds, then restarts.

DESCRIPTION OF BEHAVIOR: The engine just dies. The van coasts slower and
slower, rpms dropping on tach, then the engine re-starts (if the van has
not slowed too much, otherwise, have to use starter).

OTHER INFORMATION:

1. This is not a random cut-out, but quite periodic. The hotter the day,
the steeper the climb, the more frequently the engine cuts out. On a
moderate grade, the engine will cut out every 45 seconds; as the grade
steepens the engine dies every 15 seconds.

2. Duration of no-power lasts about five seconds.

3. The fact that the tach gives a signal when the engine is not
providing power indicates that there are ignition pulses, yes? So this
is possibly a fuel delivery issue?

4. When engine is running, all instruments indicate normal operation,
the O2 measuring gizmo shows normal bounce-bounce action.

5. When the engine is dead, the O2 gizmo is dark -- neither rich or lean
condition indicated. I tried to see what happens when the engine
re-starts but it happens very fast but maybe the bouncing bars come in
from the "lean" direction. Again, pointing to a fuel delivery issue?

6. These grades are steep enough that I run either in (auto trans)
second gear at about 2500 rpm, or 1st gear at about 3000 rpm. Thinking
that maybe the AFM was sitting on a flat spot I tried wiggling the gas
pedal but it did not change the behavior.

7. It's fairly nerve-wracking to be a couple miles from the summit and
have the engine die one or more times a minute.

8. Once the road flattens, the engine runs fine. If the day is cool, the
same grades do not cause the problem.

CALL FOR IDEAS: I won't be able to try things one at a time and see if
they fix the problem. The drives are too long--hours--in hot weather up
steep grades not immediately around here. So what I'd appreciate from
the group would be a list of candidate parts I can replace over the next
couple months and then, on our next big ol' camping trip up the sides of
mountains in summer, we can see whether the problem re-occurs.

FOR YOUR AMUSEMENT, MY BEST BUT PROBABLY SILLY IDEA: Bubbles in the fuel
line. The regular, nearly clock-like periodicity of the cut-out makes me
think of those old school Christmas tree ornaments that have bubbles
rising in a tube of water. The hotter the day, the more bubbles; the
steeper the climb, the more bubbles.

(When replying, please trim as needed.)

--
Jack "Rocket j Squirrel" Elliott
1984 Westfalia, auto trans,
Bend, Ore.