Ok, I Am Officially Getting Tired Of This Crap

So while my situation is different I do live at 5000 to and have gone up to 7,000 feet. here are my experiences:

Engine has been completely rebuilt from the ground up by Jimmy Strauss. The carburetor is a weber two barrel. The exhaust system is Clifford. Jetting originally is stock From Weber. Even with running ridiculously rich, at 7,000 feet, my spark plugs being wet, having to use the silly nonsense green fuel California residents are told to use , I have never experienced any of the symptoms as described in the original post. Now having re-jetted the engine I can tell you the jeep runs substantially better now.

You have some kind of fuel delivery issue.

 

Ditto on Seafoam. "It's good for what ails you."

And also - when I had very similar trouble it was a clogged fuel filter, which only acted up when climbing hills. A failing fuel pump can do the same.

 

You need the new jets , for the altitude. Then you Tune to that . Basic fuel filter & fuel line check , too.

 

Possible the difference is the change in terrain, not the altitude? If so, you'd only see fuel starvation when you need constant extra throttle for a long time, like on long hills.

 

The fuel was not very old in the tank but who knows how long sitting at the station. Not likely long as the stations I use are pretty busy, but who knows. I’ve used SeaFoam before but haven’t lately, so I’ll stick a can of it in the tank. The way it acted was classic vapor lock even though the temps were not high. I’ve got rods for altitude and of course forgot to bring them. Next trip along with the NOS AC pump. But I’m thinking the rods would be an all the time issue, not a running fine, then cut out, wait 5 and then it goes again. The more I think about this, the more I’m coming back to vapor lock and adding an electric pump to supplement.

 

A jetting issue would cause it to run more rich at altitude. That would cause a stumbling issue combined with a very rich-smelling exhaust. It’s highly unlikely that it would cause the engine to just quit.

I agree that it could be a failing fuel pump, but the fact that it repeats the symptoms during its yearly trip lends me to shy away from that. A pump usually doesn’t die over the course of years. And if it is just a weak pump, the weak fuel pressure could also be lending itself to the ultimate issue… vapor lock.

Check all your fuel lines’ proximity to exhaust components; especially on the ‘suction’ side of the system. A simple heat shield could fix this.

So what did you think it is?
Edit: you just answered that.

 

Vapor locking.

 

Going back on my memory, I got several custom rods for altitude made for me a couple years back in anticipation of this move to altitude since the game plan is to leave Willie up at the cabin. As I remember the story, The Carburetor Shop had purchased all the stock, etc., years ago and had the machines to create these rods. That is part of the final solution, but I don’t think that has any thing to do with this cut out, wait 5 and go.

 

I've been having the same issue with my dauntless, drive it around just fine then bam! Stops running like it ran out of gas, wait a minute or three and off she goes. Just got done emptying/cleaning gas tank, new fuel filter(s), electric fuel pump, new fuel line. Ran great for a day then bam! Next step is having the carb rebuilt.
Some have suggested it might be an electrical issue, maybe a bad coil. Process of elimination I guess. I'll be following along on this thread to find the outcome. Been told that a rubber fuel can deteriorate from inside and have a hanging flap that drops preventing gas getting to the carb.

 

I do have to add, that driving Willie up here in the crisp cold air, with tall pine trees and the windshield down, is very relaxing. I just have to stay close to the cabin until I get this solved.

 

i had the same issue, only with my v6. i remedied the problem by installing a fuel pump with the return line to the tank. PO had the wrong one. i also installed a heat shield to protect the pump from the close proximity to the exhaust. Another item that a PO forgot. no troubles since. heat and high altitude are a bad combo. vapor lock. good luck with it.

 

Yep. Possibly a restricted fuel pickup (clogged), pinched fuel line, or the fuel pump. They usually run just fine at high altitude without changing jets.

 

He does state that the change in Elevation is when he started experiencing this problem, though .

 

he makes this move every year so we must look at what changed from last year. So rods and jets are out since they don't wear aside from grime buildup.

 

Every september stations switch to winter blend fuel which is cheaper (for them) but its worse for us. It evaporates easier and boils easier. I wouldnt be surprised if they made it much worse this year. Alot of people seem to have this problem this year. Iv had it happen on my neighbors mower. All summer it was fine. The beginning of october he had problems so i had him run without the hood sides to let the heat out and its been fine.

 

I hope he let's us know when he solves it ?