I have a 1982 Vanagon with a Subaru engine. I'm not at all mechanically minded. The problem I'm having is that when I'm on the open road the fuel doesn't seem to be getting through properly. It feels like the van is running out of gas. It will slow down and then surge again. Especially going up hill. The van slows down to a crawl. If I stop and shut off the engine, then restart it, the van will run fine for a few minutes before the problem starts again.

I'm assuming it's something to do with the fuel line or pump. Any suggestions would be most welcome.