Intermittent issues can be any number of things, but I would look at ignition first. Do a search for HEI conversion and get rid of the Duraspark module. In a nutshell, you take a HEI distributor from a 80's Chevy 6 cyl engine (find at a local u-pull yard), change the gear, replace the cap and install new wires, open the gap on the plugs slightly and you're good to go. Most people can have everything done for under $100. Then do a search for Nutter bypass. It will talk about disconnecting the metering pins from the back of the carb. There's a good chance doing this will cure the intermittent engine problems.
1986 CJ7, 4.2 w/4.0 head, TFI-HEI hybrid ignition, Clifford manifold w/Holley 390 w/cold air intake, OBA, 4.5" lift, Woody CV shaft and Tattons in front, 4.10 gears - lunchbox in front, Truetrac in the back, twin-sticked, blower upgrade for running topless, trying to keep it simple.
It's just a Jeep, and if you don't wheel it once in a while, it's not even that.