Ok I've been out of the game for almost 30 years and just now pulled a spark plug wire off the plug to show my son stuff I should have showed him 20 years ago. Now when I put the rubber wine bottle like thing back into the hole it does not stay in place. Good for a while then it pops out again. Any ideas? Thanks.

 

Bet the wire pulled up a little before the boot came off the plug.

 

Buy a new set of wires.