Weird dying and starting issue

Okay,
2000 xj, 4.0, aw4, stock motor and trans and electronics.
A few weeks ago I had problem where it would crank good but not start. Naturally I searched here and found out how to fix it, change the Crank Positions Sensor. I put in the new one (pain in the butt!) and she started right up!
Well after a week of no problems, I get a new problem. I'll be sitting at a light or stopped and it's idling fine and then all of a sudden it dies. I put it in park and it cranks but doesn't start just like before. The weird thing is if i put it in neutral and roll it back or forward a few inches it fires right up.
What the heck????
Also, once in awhile while driving it will wierd shudder, and the guages go blank and then come back on like it died for a second.
Thanks in advance!
Chad

Well, the NSS will not kill your motor, but it could prevent it from starting. The rolling back or forward, in neutral, shouldn't make a difference in the relationship of the flexplate and CKP that cranking wouldn't do.

All that said, I would recommend that you check the CKP wiring. Make sure that the connector is clean and the harness is not up against something hot.

Whenever you change and/or fix something, and something strange happens afterward, you need to go back and check what you did.

Also, what brand and where did you purchase the CKP?

Make sure your Crank Position Sensor mounting bolts aren't loose. Look at the wires for it and work the connector some by unpluging and replugging a few times.

IMHO, NSS could prevent cranking, but I don't think it will prevent starting if it is cranking.

Winterbeater is right, the NSS could prevent the engine from cranking.