388, draws fuel from ONLY left tank!

I first noticed this problem last winter, when the outside temp would get really cold (below 20F, maybe below 15?). As soon as I got in warmer temps, the problem would go away. This is a company truck, and the shop won't "waste" time on a problem that is not occurring "at this moment."

Same thing started this winter, but now when I get back in warmer weather (two solid weeks in 60+), it still won't draw any fuel from righthand tank. Well, not quite. In the warmer temps it will maybe draw 1/3 to 1/10 the amount of fuel from the rh as versus the lh.

Since the problem is now so obvious, the shop will look into it, but it probably means removing the tank, and sending it to an outside shop, which is either going to mean a week or more downtime for me, or getting in a Volvo (yuck!) while it is fixed.

Any ideas what could cause this, though?

 

No, not exactly (I thought I said it kept up when I got in warmer weather?)

Anyway, drove it into the shop today to write it up, again, and it was idling rough, got an active fault on the Road Relay that said low fuel system pressure. After I shut it off for a half hour or so, it would not start again. Plenty of fuel (even with the only one tank deal), so now the shop does have it, and will send it to Peterbilt or Cummins, tomorrow.

I'll be glad to have it fixed, I hate driving in bad weather, and having to worry about the truck breaking down on top of that. I'll let you all know what the outcome is as soon as I find out.

Thanks for all the replies.