Know this is a little after the fact, but I have 27' 1991 Tioga Montara on the Ford Chassis with the 460 fuel injected. I've been fighting vapor lock this summer. Thought I had it whipped with new fuel pump and filter, but happened again this weekend. Definitely heat related, happened 3 times on the way home yesterday, ran great after cooling off some. Had run 250 miles before without problem, then ran 100 miles home last night after it got cooler. 2 fuel pumps on this model, one by motor and one in tank.Haven't replaced one in the tank. Doesn't make sense heat would effect it - it was only 80 degrees outside. The mount where the filter and pump are located was too hot to touch when it stopped. Only 60,000 miles, runs perfect otherwise. This one has me and the mechanic stumped. Any other ideas???