I have an AE101 AT. Just this morning, I saw my distributor having little sparks while engine is turned on and upon inspection I saw that there's a little hole, a slit, a very short slit. I don't know what cause it and it does nothing (yet) on my car. It still runs okay aside from most of the time you have to turn the key twice to get it running (as I have read distributor problems can cause hard starting). Is it critical? Do I have to have the distributor check for any problems or do I just need to replace the cap or just put something on the tiny little hole to cover it up?

Thanks in advance for the suggestions and answers.