Hey curmudgeon! Checking in to see how your new standpipe install went and if its' helped with your altitude issues with your espar. And I'm still not clear how the new pipe installs. Does it thread into the existing aux tap or did you have to drill a new hole to thread it into?
FWIW, as a "full transparency" reminder (mentioned in another thread
), my current Espar S3 B5E implementation is on an E-350 Econoline van, to help educate me in prep for a Transit high roof "Version 2" conversion. But I believe the fuel pump implementations are VERY similar between the two. In any case, on the Econoline, the fuel pump is plastic (as is the tank), and comes in two versions, one with an auxiliary fuel port and one without. Mine does not have the aux port, but the area where it would go, including the vertical line (mostly open area) that would have the 6mm plastic tube is available. So I drilled a hole in the top of the pump there and dropped my Espar 2mm standpipe down into that vertical space. An advantage of this is that if I screwed anything up in the process, I could buy a new fuel pump (rather than a new tank). This also allows me the option to simply remove the system if I want to put it in a different vehicle or if I want to sell it without the Espar mod. So you could look into whether that's feasible on the Transit fuel pump. The available place to drill that accommodated all the functional requirements was a tight fit, in that I had just enough space on the top of the pump to get the stand pipe in, not overlap the edge of the fuel pump lock-ring bracket with the top of the standpipe fitting, and on the inside top of the pump to still have enough access to get the nut on and tighten, while limiting to the region where the standpipe could go down all the way to just short of the bottom of the pump. So marking the drill hole in just the right spot was critical. (There was plenty of space for the vertical pipe itself). And again, this is on an Econoline, so there may be important differences or issues to consider on the Transit.
Alternatively, it shouldn't be a big deal to patch a hole in the Transit plastic tank if you decided to just drill into the tank and you wanted to remove it in the future. If you do drill into the tank, it makes sense to do it near to where the fuel pump is mounted, because that is more or less in the center and less susceptible to slope-induced issues when the fuel level is low.