03 Lerado miss fire.

I have an 03, 4.0 Automatic Lerado that drive's fine. 260K+ miles. 4 Wheel drive everything works wonderfully however! On occasion it will buck and grind. . . . Turn it off, 30 second later start it up and it's good to go for another hundred or so miles.
We've changed all the sensors (crank shaft, cam shaft, oil level etc)
Can any of y'all help me with this?

Id try some different gas, and run some sea foam or lucas cleaner through it. have you checked any of the plugs or anything?

The XJ has under went a full tune up (Plugs, wires, cap and injectors) the filters and all the sensors have been routinely changed. Roughly 30,000 miles back the computer had been changed.

Take the ecm out, take the cover off and see of the screws that hold the cover on are to long. Even the reman ecmz came with the same screws. They are to long and touch the board causing it to short out.