I'm leaning toward fuel issue myself; as I guess most are too. Otherwise, there'd be a flood of suggestions to augment what Cliff has said.
For instance... This was the crud that came out of my filter after only 40k miles.
I verified I had a delivery problem, even after replacing a pump that went bad by taking it for a drive w/ the fuel pressure gauge taped to the windshield...
But, we can get into that - one step at a time, I recon.
