I have a 1998 2.8L 5 speed Quattro. A few weeks ago, the car started becoming difficult to start. Then, it wouldn't start at all. Turned over fine but wouldn't start at all. Turned out to be the cam sensor. had it replaced. The car starts now, but takes about 10 seconds of cranking to catch. The battery is pretty new. I'm thinking that it may either be a fuel pump, or some kind of vacuum problem. Almost like all the fuel is draining back into that tank. If I start it shortly after shutting it down, 10-20 minutes or so, it's fine. The car also runs fine which leads me to believe that it's NOT the pump. And there are NO check engine lights on either.

Any suggestions would be helpful.

Thanks