does it fire up when it is cold and get worse as you drive? if so it's your crankshaft sensor at the top of your tranny bell housing.
to test the crank sensor, boil water stick it in the water and test it when hot. the heat from your torque converter damages those things. They are only made of plastic and is susceptible to heat damage. They will usually work when cold and flake out when hot.
I just reread your post and yes, it sounds exactly like a crank sensor issue, had this happen twice in my life time.
94 ZJ 5.2L
07 JK 3.8