Help

Okay here's a problem that's got me baffled, I drove my truck to a local Volvo shop on the 9th of June for a few minor repairs, brake adjustments and to install a new fuel filter housing,(There was hairline crack in the top of the housing were I could see air bubbles) 1st one i bought from AMAZON, it didn't fit, 2nd and 3rd time bad parts from Volvo dealer, finally after new housing is install shops say they cant get truck started, I've replace fuel pump, lines and all the fittings, now the truck will only start if they take off the fuel filter and refill it, but will not stay running, all of this and still no codes are showing, Now they're saying it could possibly be bad injector cups, anybody ever have this issue with a 2012 Volvo D13 425hp before, I know these engines are notorious for injectors and cups going bad but I wasn't having this issue before I took it to the shop. Could it be a bad fuel/water separator?? Any suggestion at this point would be greatly appreciated thanks!!