Help me diagnose this 2.5TDI

[insus100]

Hello, I recently purchased a C5 Allroad with the 2.5 TDI AKE engine (300.000KM / 186.411 mi) to restore and put back in the road. I bought it from a mechanic that said he changed the injection pump, 5 out of 6 injectors and restored turbo. Car smokes a lot until it warms up and rides for a while. If you step on the gas pedal it smokes even more.

It has some issues, i'll explain below.
I scanned it with VCDS and there's no fault codes except for some sensors for the air suspension. Engine has no codes.

First, the fuel line that goes to the injection pump fills up with air when off, and it's hard to make it start. When running there's bubbles in the line (video below)


View: https://youtube.com/shorts/Ep2FvLp19lI

Also I don't know if the engine is running fine, I attach videos of what I hear and see below.

View: https://youtu.be/UMdpk46xgt8

Here I can hear the engine making a pompompom noise, can you hear it? what is it?

View: https://youtu.be/V4wlMBUAVjU

and here the exhaust (is it misfiring?) I guess with all that air in the fuel line:

View: https://youtu.be/GAscMq1OY7w

I'm no mechanic, this is just a hobby for me, I just like messing with these because when they work they're awesome.

I'm going to check the pump timing with TDITiming in VCDS, but does anyone know where should I start from? I need to pass emissions in the car inspection to make it road legal and I doubt it does right now.

 

[insus100]

So the problem was worn out camshafts and missing rockers (obviously).

So I got refurbished heads with new (non original) camshafts and installed them but now I get no compression on every cyl and I can't get the car to start!
Timing is correct I've checked it like a hundred times now. Engine turns manually without issue. But no compression. I tried lifting cams and pouring diesel into intake, it stays there so valves on intake are sealing. Not sure about exhaust. Do you know what could it be?