1kd-ftv engine woes

Engine was rebuilt, customer had it rebuilt earlier in the year but shoddy workmanship and issues were pending until it started knocking again and he was experiencing a loss of power and cutting off problem prior.

1. Standard procedure for me as ive built dozens

2. Engine started and idled for about 30mins then started to rough idle and black smoke

3. Cut off and refuses to start and idle, it starts and stays on for 2secs and cuts off

4. Fuel pressure was present, replaced injector driver, other set of injectors, checked ecu for any blown transistors and cold soldering, replaced fuel pump(used), rail(used),

5. Crank sensor replaced, removed some silicone that smeared on the trigger wheel, engine cranks and turns over better but does not stay running

6. Physically check fuel pressure by slackening the lines with old and new pump and fuel is leaking down rather than spray out as compared with another vehicle. However fuel pressure matches target pressure on the scan tool(using toyota techstream)

7. Best news of all is no fault codes present except for the turbo vnt jack which is out due to the brittle plug that needs to replace. Can a stuck vnt ring stop a van from starting?

8. Next step is to recheck compression via gauge and confirm all cylinder healthy as when check by touching each exhaust port the cylinders are firing and are hot. Only issue i encounter in d engine rebuild was the ring squeezer shifted on installing no.4 piston and broke a ring which i replaced and reassembled with ease.

9. What ia beating me is the engine started with no problems and just cut off with no strange noises or any sort of irregular snaps, jus black smoke and rough idle...

10. Compression test was done, 400psi avg all cylinders dry, 450 wet.

Any assistance is appreciated