2004 Nissan Maxima VQ35DE 245k miles original motor.

Car ran fine but poor chain slapping around and killing the engine on occasions randomly.

So, just completed timing chain, guide, vvt sprockets, all gaskets from everything that got taken off put on. Used second chance repairs guide on changing it out and followed it to a tea. The car went from 2 nights ago cranking but not turning on to the next morning turning on after some attempts, now today to easily turning on the first attempt at turning the key, so the car runs and drives, I drove it about a quarter mile and back. I've warmed it up multiple times it starts fine warm and cold, temp is good, oil is making its way to the top of the engine on the cams and has pressure everything checks out just 2 issues now.

The 2 issues that are occuring with it are, 1 there is a slight knock it seems like speeds up when car gets reved slows down when idle sounds like just from 1 rod/cylinder. The main issue that is concerning me is that when I rev the engine lets say from idle to 2k rpm (havent gone higher than that yet just to be safe) I release the pedal and the rpms come back down way to low around 300-500 the car rumbles and then stabilizes back to normal idle 600-750 rpm. I believe that I did everything correct timing wise given its an interference engine and it would've not started at all I feel like if it was wrong.

When I had the car open cam lobes were flawless given original motor and the age. As for the timing area, every guide was failed. plastics all gone the guide on the right thats held on by 2 bolts in between water pump and cam sprocket was gone just the "I" left not an "L". One of the vvt sprockets I took apart and it was mauled on the inside, the metal that goes around the spring part was split in half and it had to have been making the timing off before i took it apart.

Overall just looking for the advice on diagnosing the two issues that are occuring. 

Thanks!

[edited for language. -mod]