Timing Issue?

[Jeff Dev]

My truck just cut out yesterday. No sputtering. It was as if I simply turned off the ignition. After trying to turn it over for a while, it finally started, but ran horribly... As if it was misfiring and igniting exhaust. Then after stopping the engine and starting it again. it was fine for about a minute, then cut off again. After start up, ran crappy again. After messing around with the truck all day, I can safely say this is now it's M.O. It will run fine for about a minute... Dies... Then becomes difficult to start... When it does, runs rough until I turn off the ignition. After starting again, runs great for a minute, then cuts off again.

I pulled each plug wire at the time when engine is running rough and all were firing fine. I checked the plugs, wires, cap, and rotor.

Then I checked the timing... When the truck is running good, timing seems fine. When the truck is running rough, the timing jumps all over the place.

We checked the OBD (1) code which was 34, and it suggested the Detonation sensor is bad. We bypassed the sensor with a 560K Ohm resistor and the problem did not change.

I removed the resistor and left the knock sensor disconnected. Still... No change.

Now my buddy thinks the ECU may be bad, so I borrowed a friends truck (exact same truck) and swapped her ECU for mine. Her truck runs great with my ECU. Then I put her MAF in my truck... Didn't work. Even tried swapping out the throttle control... Didn't work.

Anyone else have an idea what can cause the issues I am having?

1994 Nissan D21 pick up
V6 4WD
Manual Trans

I graciously thank you in advance