I was recently restoring an old Volvo 242 DL from 1981 since 1 year. We did work on literally the whole car and nearly finished the project.
We´ve already put massiv work into the ignition system because the Volvo was imported from Sweden and had a lot of problems overall.

A short time ago i forgot to reconnect the High Volt Cable at the Ignition coil while starting the car.
The High Volt jumped over to low volt of the Ignition Coil. Its the Bosch bistributor with the breaker point system.

We managed to get the car running again by swapping the Alternator, ignition condenser and a new coil, but i guess the coil wasnt damaged at all but there is one really strange occuring.
The car runs totally fine at first but after warming up and choke in the car stalls in Idle by loss of spark. While giving it only a little gaspedal the car continues to run totally fine.
Of course i measured the Voltage at the ignition coil plus and at first the Voltage is fine but with a warm engine it starts dropping until the voltage for spark wont be sufficient, so the problem lies clearly before the Ignition Coil.
Im thinking about that it might draw ground somewhere and it may only maintain the needed voltage with a little bit of gaspedal which i think might be the only reason besides a faulty or too thin wire.

Have you guys ever experienced something like this or do you also think that the voltage loss somhow happens by drawing mass? Also already thought about the Ignition Key Switch.
Best regards