Citroen DS3 1.6THP wont idle after engine replacement

[Idlethumbs]

Hi all
Thankyou for accepting me to the group, I am at wits end on my DS3 and hoping to find some skilled knowledge from you lovely people.

MY DS3 developed a rattly chain and the chain and tensioner was replaced, unfortunately the crank pulley was not tightened fully and the engine ran for a few seconds, crank pulley spun and the engine got damaged.

Queue a second hand engine. Second hand engine fitted and ran fine, but it was burning oil, so the engine was removed, returned to seller and another engine second hand engine was purchased.

But this engine will not idle.

The engines chain was replaced as it went in so that there were no issues down the line, timing was done correctly, full locking tools, dummy tensioner, correct degrees etc so happy with this bit.
The vehicle starts and runs, if revs held at 1500 rpm or more the engine runs sweet but on idle it chugs like it is trying to die.
If the turbo or maf are unplugged then the engine idles perfectly which suggests the base engine is good.
Have tried the old and new turbo, no difference.
Have swapped both oil solenoids that control the VVT pulley (top and sump valves) no difference.
Fault codes vary depending on the vehicles mood...it appears. Fault codes to do with VVT link.
The VVT has been swapped also between the supplied engine and the original and the VVT pulley aligns correctly against its markings on both suggesting no issues with it.
Air inlet has been smoke tested and have no air leaks.
The vehicle has the cat refitted so all sensors are plugged in and working, the rest of the exhaust is currently still not fitted.
The VVT pulley when looking at live data shows a reading of -35 degrees with the air system connected which I believe is incorrect, with the air system unplugged it reads around 0 and runs well.

I am loathed to say the engine is no good when it idles lovely when the inlet system is unplugged.

Any Citroen boffins have any ideas, I feel like there is a nugget of wisdom somewhere?

TIA for anything you can help with.

[mickthemaverick]

You may get an idea from this site but only a list of maintenance tips for your engine: https://www.etuners.gr/peugeot-citroen- ... icing-101/

[xantia_v6]

Which variant of the THP engine is it? (HP?)