Volvo v50 crank no start

[adonisis]

Hello, i bought a volvo v50 2007 2.0d (PSA engine) a year back, and it was running rough and missfiring like crazy and was low on power. so i managed to narrow it down to faulty injectors quite fast, and changed those and it was fixed. The engine ran like new and had regained it's power. but still afterwards sometimes when i drove it just wanted to die mid drive at any rpm and almost shut off while driving. so to be safe, i changed out the the timing belt as it was due a few miles ago, and i locked both camshaft and crankshaft with a couple of 8mm drillbits and changed it. triplechecking the that it was correct. (i also had to disconnect diesel lines to reach everything).
i mounted everything up and tried starting after bleeding out the system, but no luck. the car just cranks with no apparent fault codes. the engine threw a few codes like cam sensor and alternator low voltage when the battery was drained, but i read this is common due to the low voltage triggers the cam sensor code and the engine thinks the alternator is no working when battery voltage falls too low.
I started checking if i bumped a sensor or something and saw i had scuffed the rubber on the crank pulsewheel disc and replaced that just to be safe and the cam sensor with throttlebody sensore and diesel pressure sensors as they were cheap and easy to do. i bled the thing again and still crank no start.
after this i managed to get a hold of a Vida to properly check diesel pressure and other sensor values, and i noticed the diesel pressure spiking to 150-500 bar upon cranking but quickly dropping down to just 40-60 bar after the peaks. so after this i determined it had to be something with the diesel system, maybe the diesel pump was dying and that was the reason the injectors went bad? but i am not confident in this yet to change the pump as i fear the issue might be some other electrical gremlin issue and i'm a bit over my head here. the local shop can't help me much as they suggested to start changin cem and random shit for almost no apparent reason for way more than the car is ever worth. does anyone have any clues or advice to how i should proceed here? i got a few pics of the diesel pressure curve and some other values and i can go get some more if needed.