I'm looking at buying a 1993 Nissan Altima, but someone who knows the seller told me that it stalls at random while driving. The seller doesn't seemt to know why, in fact, that's the reason he's selling it. Is there anything that could be causing this? This car's condition is mint and the owner seems to keep up on his repairs, so I'm a little stumped. Any thoughts or questions that I might ask the seller that might help to narrow it down? thanks.