Itinerant Air-Cooled

Recently, my bus has been acting up just after I start it in the cold after sitting for a long time (like more than a week). (Cold being relative here: it's about 45 overnight with some morning fog). Here are the symptoms (2.0AVP with original solexes):

1. Tap tap on the gas pedal, bus starts well and runs well right away.
2. Third tap brings idle down to reasonable level (a little low but it keeps running).
3. I start moving but have no power at all and occasional backfire, which seems to be on the righthand side.
4. Bus runs rough now and I blip the throttle to get it going with no success. It sometimes even stalls, but restarts easily.
5. I get out and walk around and check the chokes, both of which are open (left more fully than right but not a major difference).
6. I futz with the linkage and blip the throttle some more; sometimes this solves the problem, but usually not right away.
7. Most times I struggle to get around the block, thinking I'll ditch the bus at home and take the truck and I get annoyed and blip the throttle more aggressively with big backfires.
8. All of a sudden I feel a surge of power (like I have a Porsche or something). I proceed half a mile to the freeway, merge into traffic, and fly uphill at 65mph with ample power and responsiveness.
9. This does not repeat itself until the bus has been sitting for a while and it is cold outside in the morning.

Any thoughts? Am I killing the engine by aggressive blipping with backfires? Should I let it warm up? Any part of the carbs I can check to see if something is stuck?

my experience.
archaic induction
+ not synched quite rite
+cold weather
+chokes maybe not working quite rite
= poor running for the first couple miles driving.

my 2.0 with dual weber's does the same. i have no chokes.

the choke that is opening the most is probably the side backfiring. fuel falling out of suspension in the cold dense air.

when ever you have back fires, look over your vacuum lines, they can pop off and leak. actually that is the first thing to look for if you cant get it restarted after a back fire.

you could futz with it for ever, or do what I do, start it up 5 or 10 minutes before you have to go. leave it alone as soon as it settles down a bit. takes about 30 seconds for mine or more in single digit temps. the colder it is the longer the warm up time. i leave it running and go back into the house. mine idles ridiculously low also, the idle climbs during the 5-10 minute warm up.
if you can't wait, and have to drive it, try gently feathering the gas up and down with small movements. drive away gently when it begins to fire on all four, some judicious feathering of the pedal will be involved. they don't like any kind of heavy acceleration when cold and stiff. do not try to leap out into traffic.
carbs will never equal the smoothness and drive-ability of modern efi, 'cept maybe when they were brand new from the factory 30 some years ago.

one of the most reliable cars iv'e ever had.

covelo wrote:Recently, my bus has been acting up just after I start it in the cold after sitting for a long time (like more than a week). (Cold being relative here: it's about 45 overnight with some morning fog). Here are the symptoms (2.0AVP with original solexes):

1. Tap tap on the gas pedal, bus starts well and runs well right away.
2. Third tap brings idle down to reasonable level (a little low but it keeps running).
3. I start moving but have no power at all and occasional backfire, which seems to be on the righthand side.
4. Bus runs rough now and I blip the throttle to get it going with no success. It sometimes even stalls, but restarts easily.
5. I get out and walk around and check the chokes, both of which are open (left more fully than right but not a major difference).
6. I futz with the linkage and blip the throttle some more; sometimes this solves the problem, but usually not right away.
7. Most times I struggle to get around the block, thinking I'll ditch the bus at home and take the truck and I get annoyed and blip the throttle more aggressively with big backfires.
8. All of a sudden I feel a surge of power (like I have a Porsche or something). I proceed half a mile to the freeway, merge into traffic, and fly uphill at 65mph with ample power and responsiveness.
9. This does not repeat itself until the bus has been sitting for a while and it is cold outside in the morning.

Any thoughts? Am I killing the engine by aggressive blipping with backfires? Should I let it warm up? Any part of the carbs I can check to see if something is stuck?

Right side electromagnetic cut-off jet. Open circuit when cold. See if it is secure in its hole. See if the wire is connected OK too. That's my guess.
Colin

well there's one difference between stone age weber's and semi modern solex's.

This morning, exact same circumstances. Waited five minutes and cleaned the windows while warming up the car. No problems. It may still have been that cutoff but a quick warm-up seems to help too.

Do we declare victory?
Colin