Ok so i have a 92 xj with the 4liter. It basically cuts spark off randomly. I have already replaced the crank sensor 2 times and it still keeps doing this. Basically it will stall when ever it wants where ever it wants to.
It doesnt always stall it sometimes just blips the rpms and catches itself.

I am ase certified in engine performance but i need help. I can only figure it being one of these things or maybe a couple but spark is only stopped by these and from where i have seen measured

I have a fairly new coil like 6 months old
New crank sensor of course haha

It could be the ECU, the distributor pick up, or those other 2 things.
Im leaning towards the ECU, its an OBD1 so it doesnt really throw any codes.
Im going towards the ECU because its very very intermittent and i cannot reproduce the stalling and blips in the RPM

i have a 3 hour 190 mile drive to and from home from college and it does this when its on the freeway the most, but its starting to do it more and more in the city (this is on the newest crank sensor)

I feel that, and so does some other mechanics i have talked to, that its the ECU throwing crazy signals out to the crank sensor.
I have heard that the Chr. ECU's sometimes go bad or something idk

Any help is welcome, i know some stuff but not everything haha.

Thank you for your time in reading my essay - joe