Diesel fans:

Quick question for all of you - I have on two occasions in the past couple weeks caught a brief whiff of diesel fumes (raw fuel, not exhaust) while driving down the highway. At first I thought I had a leaking fuel line, or perhaps a loose vacuum hose. The smell came and went after a few minutes and could find nothing wrong when I inspected the car. Anyone else experience this? Is it likely there is a bad vacuum hose somewhere, or is it something else? There is the remote possibility that it was something from the road and not me, but I don't remember a smell that strong from before I bought the diesel.