10 weeks and can't find the problem?! Sounds like they never bothered other than maybe putting some fuel additive in the tank hoping that would resolve it. I would've lost my mind if they had mine that long and never fixed it. You should probably go straight to the manufacturer instead of the dealer. There's no way it could be your hoses at that age, I'm thinking like you and something might be clogging it up or even a loose wire somewhere that's no making a solid connection. Might even be your high pressure pump malfunctioning.