I think I have an idea here but looking for extra set of thoughts. Had a turbo failure few months back, replaced. Run fine for a while ( several weeks)then won’t throttle up until warm, grey /white smoke, Diagnostic showing #1 injector falling out. Replaced with a rebuilt.. no change Replaced with new.. no change. Fuel system has been drained and cleaned ( wasn’t bad at all) So… compression test next or injection pump ?
Compression test. Suspect damaged valve.
You are going to have to post more information than that. Year and serial number would be a minimum. Engine model would likely be necessary. Amount of hours on the machine and engine would be helpful.