2.0 tdi non runner! Long story!

[Weedraker]

Hi All, hope someone may be able to direct me.
I bought a 2005 a4 2.0 16 valve BLB engine code off a friend of mine after a timing belt failure.
The tensioner bolt broke, he removed it and fitted a new timing belt kit. It ran nicely at idle but wouldn’t rev just smoked. That’s when I bought it! I checked the timing which was all ok, but found broken rockers!
I removed the engine to gain access to the rocker shaft, removed and replaced all the rockers, and refitted the engine. It started ok, ran on 4 cylinders. After a few days and starts it was only running on 3 cylinders. I’ve scanned it and no fault codes showing.
I metered out the wiring to the injectors and seems ok. There was slight oil discolouration in the fuel filter so I bought a set of injector seals.
I’ve fitted them and now it won’t run at all. It fires and runs on a squirt of brake cleaner but stops as soon as it’s gone, and lots of smoke.
I’ve had the injectors out again to check I hadn’t done anything wrong or damaged an o-ring. I’ve checked the lash clearances.
I’ve has the injector wiring out and it all seems ok.
It was running on 3 before I fitted the seals and not at all now so I’m guessing it’s something there.

Any ideas on what else I can check?
Thank you for reading.
Michael

[Gazwould]

Then there's the double trouble oil pump drive of the 77mm drive key and chain tensioner of the balancer shaft modual ?