intermittent engine

ok now how to describe this is somewhat wild but while cruising down street/interstate engine will suddenly quite..i.e. engine rpms drop to zero, voltmeter starts to decay etc..check engine light will flash yet no codes are stored for the event. then suddenly rpm's come back up to where they were and everything acts fine. so far have checked fuel pressure-good, replaced all plugs, wires, dist cap, rotor button. checked resistence of coil per fsm and it was good. checked voltage at tps and its good both at idle and full throttle. even manufacturer says they cant help unless it hard fails, but am looking for answers before i get stranded on highway for this is my DD. it is a 99 xj 4.0 2wd 3inch lift. thanks and sorry for so long just wanted to include everything i have checked so far.

Crank Position Sensor....CPS

I was going to say the same thing. Sounds like the CPS or CPS plug.

Mine will start doing that about every 3 months. Unplug the CPS and jiggle the plug as I reconnect it, and I'm good for three more months.