Visited colleague in Africa. He has a 343, probably 1984 (-ish) with B19 carburetted engine that runs very rough. It was getting dark, and my last day there when we came across this problem (and it gets dark quickly near equator) but there definitely was no vacuum line from the distributor connector towards the intake manifold. I managed to see that there was some kind of plate on the inside of the left wheelhouse to which a couple of vacuum lines were going to/coming from. I couldn´t figure out where he should connect the obviously missing vacuum line, and I am not very familiar with this series of carburetted engines (which however seem very durable in that kind of setting)

My assumption is that the local mechs have set his ignition sorta halfways, so he has really poor performance at low and high speeds, but OK inbetween.

Thanks for any suggestions + Anyone got any good pics or drawings that I could forward to my friend?

Probably not in the US.
If there is an open fitting on the manifold it should be plugged.
A short piece of tubing and a nail work pretty well.
Then the ignition can be timed for better performance and idle appropriately
set. Some carburetors have the vacuum fitting on them, so it may be on the
carb rather than the manifold.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma

Thing is, I clearly saw the fitting on the distributor where I am used to see the vacuum line for ignition advancement attached in older Volvos with carburator. However, I couldn´t figure out whre the other end of [a missing] vacuum line should be fitted. In the semidarkness there was no open line or connector on the intake manifold. But, there was this funny, plastic I think, plate sitting on the left wheelhousing and which had free connectors. Couldn´t determine whether these were plugged or not.

Still very grateful for any pictures or diagrams or tips on internet pages on this issue. Is there any similarity to NA 240´s?

Do any of these B19´s have electronic ignition with electronic ignition advancement, or are they all "mechanical"?