It, along with other posts including mine, lets you know that you shouldn't be having a problem at high altitude because it isn't typical. So you can investigate further to see what the problem is.

 

Well hell, I know I have a problem, because I have been at 13+ feet before without a problem. Otherwise I wouldn't be on here asking for help.

 

You know what this makes me think of......I have a chamber vaccum packer, which I absolutely love btw, and when vac packing liquids there is a point at which even cold liquid will totally "boil" as the air is pulled out of the chamber and pressure falls (decreasing pressure creates lower boiling points). What you're saying here is the same thing I guess......the decreasing pressure causes the fuel to boil at a much lower temp than normal and the result is vapor lock in the fuel line. Your comment about unscrewing the gas cap would help raise the pressure in the tank, hence increase the boiling temp (back towards a more normal level) and keeping things happier in theory if I'm understanding. (sorry guys, I'm bit more dense when it comes to science). I've never thought about in terms of fuel delivery.

Sorry I can't add any value. It's an abnormal issue at hand and curious to see where this ends up.

 

Have you checked fuel lines for cracks

 

try a free flow air filter. Maybe you can run with no air filter in the area where your jeep is shutting off for testing purpose.

 

Hey DD - did you make progress here? Or have you not been back to that altitude again since? Just to add another perhaps check - scrounge around enough to get the plug in fittings such as stock and tap into the fuel supply line to the rails and use an electrical transducer and gauge or cannot remember if the system monitors FP which would take a online scanner to tell the same.