I feel your pain, I have a 1984 cj-7 with the same little crap motor,
I took the carb off and installed a weber carb, so far it runs much better. still no speed demon.
be sure all wires and plugs are in good shape, check all wired ends, plugin etc: the wiring system on the old jeep was poor at best and now it has nearly 30 years old of abuse.
I would suggest trying this, play around with the timing. not going to cost you anything,
with motor warm, try increasing the timing in 2 degree increments, if after increasing it 6-8-10 degrees, if you are seeing no improvement, then start decreasing it.
be sure you have all the systems set, hoses plugged and rpm's set up to make the timing adjustments per the manual.
I was able to secure a 1984 amc shop manual like the jeep dealer shops had, these books give a lot of detail info, the books you buy at the autopart stores took their pictures from the AMC shop manual.
try this on timing, as I was never able to get my jeep to run right at the factory timing settings.
do you have the correct fuel filter and have it installed properly, proper air filter with pvc hooked up
note to file: these little motors are not barn burners, even when running their best.
the 4 banger that amc bought from general motors up through 1983 was a much stronger engine, but amc wanted their own engine, so we got stuck with a lesser engine,
run some high test gas in the tank, if you can find any, I always used high test, but now use non ethanol as it is still available in my area.
might try some fuel additives such as sea foam, octane booster, etc:
good luck and let us know how it goes.
have you heard of the nutter bypass, if not read up on that, might the answer to your problem if no emission test are required in your area.
the little engine in my jeep will take the fuel fine, but again, its no pavement burner as they do not have over 80 some horsepower. The 6 cylinder was a much better choice of engine for this vehicle.