jeep about left me stranded @ Mcdonalds on my lunch break
96 JGC 4.0 4x4 My jeep died on me @ Mcdonalds and it took a good 5 minutes to get it cranked...while on my way back to work it was spitting and sputtering and dying the whole way back.It did throw a CEL.. So i left the jeep at work that night and the next day i came back to take it to Autozone,it made it there fine no problems...They printed something off the computer to give to me because they couldnt make any sense of it so here it is Troubleshooting P1391 Definition: CMP or CKP signal intermittent condition. Explanation: The ECM detected the actual CMP position disagreed with the expected CMP level. Probable cause: 1. Timing belt or chain stretched or jumped. 2. Defective CMP sensor It would really help to know what the CMP or CKP sensor is
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.