Lately if I shut the car off and immediately try to restart it, it won't start. The engine turns over, and it doens't sound like it's cranking too slow, but it won't catch. Does this sound like the starter is too hot, or is it something else? I've got headers, but they're ceramic coated.

 

Check your battery to make sure it doesn't have a dry cell. Also, make sure the alternator is keeping the battery charged. You could also have too much timing, bad ground or bad battery cables. That should be enough to get started with.