You will usually get a little more response posting in diesel discussion.
It sounds like you may have lost some vacuum. You need to inspect the vacuum system. Start looking at/around the hose that runs from the vacuum pump to the vacuum booster. Not real sure why they would be working on that side of the car to repair the oil return but it sounds like something got knocked off or broken. That baby ain't dieseling - it's running
which is caused by not enough vacuum to the shut off valve. You got a MightyVac don't you? Get it out and start troubleshooting.