Help. I have a 99 Magnum 500 that starts fine, runs strong.strong. It started running rough for a second or 2 after going through a puddle. Now it runs for around a half hour and then dies. Let it sit for 15 or so and it starts back up and runs fine. I cannot figure this out. I can't get it to die in my shop, only on the trail so of course the plastics are all on.

 

Have you checked to see if the gas cap vent line is kinked or clogged?

 

yes, I even loosened the gas cap just to see if it made a difference
I also checked the fuel pump. It seems to pump out a nice pulsating stream when cranking, but this is in the shop when it still runs.