John, in reading all that you have done in tuning and troubleshooting your YJ, it sounds like you might have some contaminant in your fuel that is causing an intermittent problem.

I'd suggest checking and/or replacing all your fuel filters. You also might have a slight amount of water from condensation in your fuel tank. You could try dumping a couple of the small bottles of "dry gas" in the tank and see how it runs after the present tankful has been used and refilled.

1977 CJ-7, fiberglass body, AMC 360 w/ headers, DUI ignition, Edelbrock intake and Holley 4150 carb, TF999, Dana 300, 4.56 gears lockers, York air comp, 4" susp lift, 2" body lift, BFG 35" M-T tires, Megashifter, AGR pump & box, REP8000 winch.