Please help guys, starting issue!

[Teammattblue]

Evening guys, looking for help with my fab 1.9tdi pd elegance please

Long story short, it started to really run awful on cold starts, coughing and spluttering almost feeling like a miss fire. , when warm struggling to get any boost, and going into limp mode. Then 2 days ago and ever since it has failed to start at all, its just turning over and not Even attemting to fire. I've tried changing the injector loom as I heard this was a common fault but hasn't solved it. Also fitted a new fuel filter and tried swapping the maf and map sensor out, to no avail. The glow plug wiring where it connects onto the plugs was also perished, so I replaced this, still jot solved. Has anyone got any ideas? Thinking along the lines of maybe a failed crankshaft sensor which could have made it run bad as it was failing?(although rev counter is showing about 350 revs when turning over) High pressure fuel pump Or maybe glow plug relay(although I wouldn't have thought this would cause a running problem when warm??) Have had it plugged into diagnostics but no faults found Any ideas would be welcome. Cheers guys

[sepulchrave]

Check the top end, you may have a worn cam and followers, has the correct spec. oil been used and changed regularly?

[Teammattblue]

Tbh its due an oil change 

[Declan-Carr]

Sounds like your injectors need to be serviced, if you know of any Diesel pump and injectors service. Call into them and cut out the middle man. You might finid them in the yellow pages.