Vapor lock on in tank pump?

Hmm, not sure how the pump is connected since I bought the whole tank as a unit. My guess is that it's just a rubber hose clamped on both ends so that you can replace the pump fairly easily. It's an Aeromotive adjustable regulator with a vacuum reference. It started up fine after sitting for a while and drove around like nothing was wrong yesterday, so I don't think it would be a broken line or I would think it wouldn't be working at all. When I went back to it the day it messed up after a few hours and keyed it over it went right up to full pressure again, which is why I thought maybe vapor lock since it was a temporary problem (I didn't touch anything between letting it sit and going back to it later), but I'd never heard of that on a high pressure in tank pump.