CJ stalls only after high speeds

[Skynnard]

So I've been having this same problem for awhile now, and I still can not figure it out. I am very new to all of this so please try to use lamest terms as best as possible. I just got done stress testing my CJ driving it around for about 2 hours under 50mph. Whenever I try to take it on the freeway it will make it to the destination, assuming I don't need to stop for gas, but then will bog out after sitting for a few minutes. The idle slows way down. It sounds like the idle skips a beat as it is slowing down. I can drive for 2hours under 50 but I can't go 15mins at 70mph. In order for it to turn back on, I need to wait a few HOURS, which is a kinda big issue.
I have replaced:
-The fuel pump
-The carb
-The fuel lines
-I have cleaned the interior of the gas tank
-There is no vacuum leak

I do notice that my oil pressure gauge does slowly fall lower and lower as the jeep runs. But I honestly couldn't tell you if any of my dash gauges are accurate.

 

[Lumpy Grits]

Try this-Do the high speed run with the gas cap off.
It also sounds like vapor lock induced from the higher under hood temps from the high speed run'n.
Make sure your fuel lines are well away from any exhaust pipes/mufflers.
How hot is your coil get'n?
Do you have the fuel filter with the 2 outlets? If so-is the smaller outlet at the top(12 o'clock)position.
OEM ele oil psi gauge is junk.
LG

 

[Hedgehog]

Sounds like yout power valve isn't releasing or stopping and she's loading up. If you shut down will it start back up again?

I'd agree with the vapor lock, except it doesn't slow down or stop while your running at high speed. I like the idea of running woithout the gas cap on .... don't do it with a full tank though.

Oil pressure will drop as you oil heats up. This is common and not to worry about unless it drops too low, then bad things happen.

 

[Skynnard]

Try this-Do the high speed run with the gas cap off.
It also sounds like vapor lock induced from the higher under hood temps from the high speed run'n.
Make sure your fuel lines are well away from any exhaust pipes/mufflers.
How hot is your coil get'n?
Do you have the fuel filter with the 2 outlets? If so-is the smaller outlet at the top(12 o'clock)position.
OEM ele oil psi gauge is junk.
LG

I will try the gas capless run. The fuel filter looks a bit funky compared to pictures I looked at, I may be looking at the wrong part. But if I'm correct, my fuel filter is actually facing the gas tank return hose down.
*EDIT* The picture I attached is a weird angle, the right border of the picture is the front of the jeep.

 

[Skynnard]

Sounds like yout power valve isn't releasing or stopping and she's loading up. If you shut down will it start back up again?

I'd agree with the vapor lock, except it doesn't slow down or stop while your running at high speed. I like the idea of running woithout the gas cap on .... don't do it with a full tank though.

Oil pressure will drop as you oil heats up. This is common and not to worry about unless it drops too low, then bad things happen.

Hey Hedgehog, seeing how you are from the same area as me, to give you an idea on the distance I can travel before having it stall out, last time it did this I drove from University of Arizona to Pinal Air Park and after I got off the freeway it died in front of Pinal Air Park. It seemed to handle the freeway speeds well. But I do have the stock 3 speed still in it. I did stop once on the way up to Pinal for gas and it turned on after the third crank but the idle sounded super soft, like it was about to die, so I just hopped back on the freeway asap to get it moving again.

 

[Lumpy Grits]

Relocate your fuel filter to the same level as your carb. and should be horizontal.
The outside(smaller fitting)is to be at the 12 o'clock position and is the fuel return line. The fitting next to the return line goes to the carb.
Bet this'll stop your hot and die'n issues.
Get a new filter--
LGt

 

[Hedgehog]

LG has a great point. Your fuel filter does seem to be backwards. the line from the pump should be on the single hose side, the bigger line goes to the carb.. The smaller one is the return, to the tank, line and should be on the top. I hope this is your problem and is an easy fix.

Yep we are close, the weather has been fairly decent lately, cooler anyways. Make sure to stop at "Willys Works", Rob is a wealth of information, buy from him if you can, he'd be a terrible source of information and parts to lose.