Hallo brothers,My father had a wj laredo 99,Some times the jeep engine turned off Stop work suddenly when driving at 70 Mile and some times at idle.No Engine starting problems and it idle very well with no issues or hesitation .Thanks for help

I'm not sure what year models but some grands are having PCM grounding out problems Google Grand Cherokee PCM problems

Had the same problem with my 99 GC and took it to a place to check computer board. They managed to fix the problem without having to replace the whole board.

what about the crank position sensor can it be bad

Yeah it could be that also

its hard to remove this sensor on th 4.0 Laredo