Tiger, If it is something like this.
![[Linked Image from i.imgur.com]](https://i.imgur.com/pUl8AF6.png)
They usually just push into side of the high tension lead and the boot hold it in place. Like NormK said they are not very good to use. They also can cause the lead wire to at the insertion point to break and lose contact. Here I use the crimp on terminals whenever I can but I do have an open barrel crimper for doing this.
The Screw in does work well as if you ever seen any of the Honda plug boot caps that how they are attach to the leads.
I was thinking that you had area somewhere between the terminal and the coil that maybe been mouse chewed in two.