Captors definitely don´t like hot weather.
When my 2cv engine (652 visa) is hot I have some difficulty in restarting it after stopping and parking.
Before, I used to park it under a shadow, sometimes leaving the bonnet open. That would usually work if the temperature wasn´t too hot.
Yesterday, as I was in a hurry, I decided to drop half a liter of cold water on both captors. As soon as I restarted the engine it immediately started to work.
Could you find any explanation for this curious phenomenon?

Captors?
What is this?

Sorry, in English the word is probably sensor...

Sensors like that are temperature sensitive, when failing. And the Visa types are known for failing. (Like the flywheel sensors on the CX 25 injection models)

There's an adaptor for the ²2cv electronic ignitions to fit the Visa engine. Then you can remove the whole visa ignition system, I believe.

Do you mean capacitor? The small cylindrical item bolted to the contact breaker points box.

Or is it the coil, from which the high tension leads go to the spark plugs?

Or the spark plug caps?

It does not sound like pouring cold water on the above items would do much good!

https://en.wikipedia.org/wiki/Citro%C3%ABn_Visa Model, History and Design .

Erik, my point is that they fail because of getting too hot. Aren't I right?
Don't forget the Visa engine adaptation to a 2cv involves the Motorolla "electronic" ignition and the two three-wire sensors. Since on a 2cv they have to be mounted very close to the brake disks, in Summer there is an extremely hot environment surrounding them. And they just don't do their work because of this ...
"There's an adaptor for the ²2cv electronic ignitions to fit the Visa engine" - where can I find it Erik? I've already tried some alternatives but the original system seems to work better after all...

Does this help?

http://forum.2cv.nl/viewtopic.php?t=5464

That's a useful link Roger.

I have a Visa engine in my AK. I used the Burton bracket to mount the sensors (and had to modify it because it held the sensors so they pressed against the flywheel!...and the bracket didn't leave room for the brake drum!). Anyway, I also had problems with the sensors overheating, so I adapted a disc cowling, fed from the (2cv disc-type) fan cowling, and mounted vertically around the sensors and the side of the flywheel & bell-housing.
Before initially fitting the Visa engine, I had an adapter made to go in the end of the camshaft, using the 123 type adapter as a pattern but adding the necessary extension to mount 2cv bob-weights and points cam, so that I could fit points. (I've lost faith in 123). I modified a points box to hold it centrally against the flat Visa casing, so it didn't float around sideways when setting up dwell & timing. I then wired the two ignition systems so that I could easily switch from one to the other. I had to use points soon after fitting the engine, when the sensors failed. I haven't needed to since fitting the cooling cowling, about 20,000 kms ago.

A Visa! My commiserations . . .