Originally Posted by newXJer

I'm new to the forum but have done a lot of reading and researching. I recently purchased a 2000 Cherokee sport 4.0 inline6 engine with 156k miles. Problems started with the common no start issue. So being new to the Cherokee I turned to this forum and found the common issue of the crankshaft position sensor. I purchased and replaced the sensor and she started back up. But then it was spitting and sputtering in idle and I got more codes with those being; O2 sensors, misfires of coil packs A,B,C. So I replaced the coil pack with brand new And replaced both o2 sensors. Still rough idle. If I leave the vehicle idle long enough it will die. But starts right back up no matter the temp of the engine. Once I put it in gear the sputter goes away and runs fine other than poor mpg. Today check engine light came back on, as I new it would (came on while in park with engine at idle....idles around 700-800 rpms). Hooked up scan tool and gave me code of p1391- Intermittent loss of CMP or CKP (Cam or Crank position sensors). That being said I have already replaced the camshaft sensor and adjusted the timing with piston 1 being at TDC and the toothpick method for syncing the camsyncronizer. I can let vehicle idle it will start to sputter then I unplug the camshaft sensor and the sputter goes away. The second I plug it back in it starts to sputter again. Just curious as to what others think my next step should be?? Am i looking at I timing chain issue? I did rotate the camsensor and synchronizer like you would turn a distributor And it smoothed out the idle a bit but it still sputters. Also could this be a reason for poor gas mpg?