Odd starting problem
 

So for about the past 6 months, I'd been noticing an intermittent delay between the click of the solenoid and the engine actually turning over. I'd say maybe 25% of the time, there'd be a brief delay, and occassionally a significant (3-5 seconds) delay. Just recently it decided to not start at all a couple times, and after going over the battery and connections (again), I decided it was time to pull the starter.

I expected to find bad contacts, but they were fine. Barely worn, in fact, nice and shiny. The copper ring on the plunger, on the other hand, was black and nasty, had more pitting than surface. I cleaned it up with some fine grit paper, put everything back together, and haven't had any trouble in the couple weeks since, so I think I found my culprit.

What's bugging me is, why did it act like that? If the ring on the plunger was too worn to make solid contact with the contact tabs, why the delay? What was going on in there to cause seconds to pass between the plunger activating and the engine turning over?

It was heating up~

Which lead to what, better conductivity between piston ring and contacts?

I'd buy that, thanks!