I just noticed that the last two times I started my car that the starter motor will turn, but the engine itself won't turn till about a second or two later. I just happened to be looking at the tach (RPM's) when I turned the key. I hear the starter motor turn, but it took about a second or two before the tach to show that the engine itself was turning.

Does anyone know what's wrong?

Also, I've noticed for a while that my idle is a bit low (about 500 rpm's).

TIA,
Terry