see, let me say this in a more comprehensive way.
you are a pawn, you hit a key, you spawn a spark at location of your pawn, but your controlled FP camera isn’t viewing the “location” where the foot usually steps on. That’s why I suggest you spawn to a different location first.
second, in a blueprint, “self” means any instance that use this blueprint to create as its class definition.
If you destroy actor, and target is “self”, you are trying to kill the pawn, not the particle emitter you just spawned.
third, if you set spawn particle to auto destroy, means it will only play once, which could be really short, and your delay will do nothing.