did you re check your spark plug wires, make sure they are in the right order on the distributor cap

 

It's an 01 cherokee it does not have a distributer just a cam sensor and and ignition coil rail

 

I am still deployed and have been surfing forums with people having similar problems after a motor swap. I found one about the cam sensor. I swapped the cam sensor from the old motor and using only my chitons manual in Which I did not see any specific instructions on how to do this other than the torque specs I came to the conclusion that this could be the problem. Since I just kind of put it in there and torqued it I did not notice any special markings indicating a particular position it fit so I figured it was ok. I am getting spark and the motor backfires so is it possible that the spark is just at the wrong times? Anyone have any links to a post about syncing the cam sensor on an 01 xj? I got a few months left so I got nothing but time to read but this is really irritating but fun at the same time. A real learning experience thanks for whatever help y'all can give me.

 

While timing COULD be an issue, it sounds to me like your starter can't turn that engine fast enough. Barely at all!

 

Figured it out it was my cam sensor I forgot to synch it to the new motor when I installed it