My brother is in AZ trying to kill an elk with the muzzleloader, he spent an extra day and a half in Alburquerque when his 2002 Dodge diesel would not run. He put on a new fuel filter even though he had that and a rebuilt injector pump and hi performance lift pump put on back in December after his truck wouldn't climb the mountains deer hunting in CO last year. Ended up at a diesel repair shop, another lift pump solved his problem. He had two days to scout, not what he hoped for after waiting 25 years for the tag, took muzzleloader because rifle was a longer wait. The truck only has about 100,000 miles on it, yes Boco, machinery is better to be used regularly, but his 100 mile a day commute would be killer in that truck, and his used to be 120 each day.

Most vehicles require a carburator adjustment to run right at higher altitudes. and again when you return to regular altitudes.