Misfire
Replaced plugs, ran better
Misfire, then deteriorated, would not run
Codes for O2 sensors
Replaced both downstream O2 sensors
Codes for crankshaft position sensor
Replaced CPS
Replaced coolant temp sensor
Verified fuel pressure with in-line gauge
Discovered distributor rotor ball bearings had disintegrated, with fragments in distributor
Replaced distributor (thought this was the issue)
Verified timing
Had ECU tested, results bad ECU
Replaced ECU with "verified" used
Replaced ECU relay
Took to Infiniti dealer
They could get it to run (very roughly) by disconnecting crankshaft position sensor
Recommended replacing crankshaft position sensor (that had already been replaced)
Did not work
Recommended replacing ECU and distributor (both of which had already been replaced). I declined
This QX4 is in pristene condition otherwise. I've completely rebuilt a half dozen other engines, so not a novice. But we (including dealership) are stumped. Help.