I just had my truck sitting for months and she started on the first few pulls. I have the check valve installed aready though. Before I put it in I could only run half a tank then my temps would hit 300 and I would shut the truck down, so I'm thinking it might be your LSN/pressure issue. I also use after run oil even if the truck is only sitting over night, always only through the carb with a few pulls to coat the engine after cool down. I don't see a problem with running the motor out of the truck, I also don't think it will help much since your not running under load so tuneing is out. The check valve is worth every penny IMO, thinking off putting one running to the carb also since I'm only useing a screen filter now.