zünden
to ignite
To cause something to explode or start burning, for example an explosive device, an engine, or a rocket.
Der Motor zündete erst nach mehreren Versuchen.
The engine only ignited after several attempts.

to ignite / to catch on
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to ignite
To cause something to explode or start burning, for example an explosive device, an engine, or a rocket.
Der Motor zündete erst nach mehreren Versuchen.
The engine only ignited after several attempts.

You can tell whether the literal or figurative meaning is intended from the subject. Technical things like an engine or a bomb zünden (ignite) literally. Abstract things like a joke, an idea, or a plan zünden (catch on) in the figurative sense.
Die Zündkerze im Auto muss ausgetauscht werden, sie zündet nicht mehr richtig.
The spark plug in the car needs to be replaced; it doesn't ignite properly anymore.
The verb 'zünden' (to ignite) is the basis for the noun 'die Zündung' (the ignition). 'Die Zündung' refers to the technical process or system that makes something burn or start.
Bei meinem alten Auto macht die Zündung manchmal Probleme.
In my old car, the ignition sometimes causes problems.
In the figurative meaning, 'zünden' (to catch on) is very often used in the negative to express that something does not work or has no effect.
Sein Vorschlag hat in der Diskussion leider überhaupt nicht gezündet.
Unfortunately, his suggestion didn't catch on at all in the discussion.
to work
'funktionieren' and 'zünden' can both mean that something succeeds. 'funktionieren' is general and neutral: a plan, a method, or a device fulfills its purpose. 'zünden' is used figuratively especially for ideas, jokes, advertising, or plans when they have a strong effect or are well received by others. 'zünden' sounds more vivid and figurative. If you simply want to say that something works in practical terms, 'funktionieren' is a better fit; if an idea suddenly has an effect, 'zünden' is more appropriate.

Am Anfang war die Idee unklar, aber im zweiten Gespräch hat sie richtig gezündet.
At first the idea was unclear, but in the second conversation it really caught on.
Der neue Lernplan funktioniert, weil ich jeden Tag kurz übe.
The new study plan works because I practice briefly every day.