Flooding?

[Kubelwagen]

So, when Colin was here last month we made many adjustments in the mad blur that was the day. End result was my 81 Vanagon is running stronger, smoother, etc. However, I think something else has been uncovered.

Since then, on cold start if I happen to need to stop at the red light up around the corner (nose up, if that matters). I will stall out when I try to go on the green. I then have to crank for maybe 30 seconds to get the engine to restart. Runs rough, runs rough (maybe 15 seconds) - then fine for the rest of the day. Feels like "flooding" from back in the days of carbs. If I try to do this experimentally in my driveway (also nose up) the exhaust does smell rather gassy.

Symptom 2. Went camping last weekend up towards Mt. Hood at just under 4000 feet. Bus great all the way there (and back for that matter). Got to the site, spent maybe 15 minutes and realized I needed to run a short errand. Bus was hard to start, just like at the light. Would almost catch, then caught, ran rough, settled out, was fine. OK, I thought it is hot, high(ish) altitude we'll see what happens when it is time to leave. Sunday came, same thing. Just wouldn't start for long enough to give me a scare. Fired up, ran fine home.

Back home (at Portland, so what 140 feet?) hard start is gone.

So, thoughts? Does cold mixture seem like the place to start? At this point is just kind of annoying (especially for those behind me at the light in the mornings).

[Amskeptic]

So, when Colin was here last month we made many adjustments in the mad blur that was the day. End result was my 81 Vanagon is running stronger, smoother, etc. However, I think something else has been uncovered.

Since then, on cold start if I happen to need to stop at the red light up around the corner (nose up, if that matters). I will stall out when I try to go on the green. I then have to crank for maybe 30 seconds to get the engine to restart. Runs rough, runs rough (maybe 15 seconds) - then fine for the rest of the day. Feels like "flooding" from back in the days of carbs. If I try to do this experimentally in my driveway (also nose up) the exhaust does smell rather gassy.

Symptom 2. Went camping last weekend up towards Mt. Hood at just under 4000 feet. Bus great all the way there (and back for that matter). Got to the site, spent maybe 15 minutes and realized I needed to run a short errand. Bus was hard to start, just like at the light. Would almost catch, then caught, ran rough, settled out, was fine. OK, I thought it is hot, high(ish) altitude we'll see what happens when it is time to leave. Sunday came, same thing. Just wouldn't start for long enough to give me a scare. Fired up, ran fine home.

Back home (at Portland, so what 140 feet?) hard start is gone.

So, thoughts? Does cold mixture seem like the place to start? At this point is just kind of annoying (especially for those behind me at the light in the mornings).

This sounds like a too-rich condition exacerbated by:
low temperature signals from the temp sensors
high elevation

Try to lean out the mixture incrementially and see if this improves symptoms.
Also, you are allowed to depress accelerator while cranking to give engine more air, just release before the engine revs up and pisses off the piston rings.
Colin