Case 580 rough running

I have a Case 580 Super E backhoe that started running rough. I had the injectors repaired and it ran better, especially at idle. The man that did the work said that if it idled better but still ran rough at higher speed when it needed more power, that was common with the Lucas pump and bring the pump in. After he went over the pump it was better the engine still vibrates at a higher speed, (between 1500 and 2000 rpm). He does work for Southeastern, other tractor companies and truck repair companies. Here is what I have done so far, replaced the air filter, both fuel filters and tightened all fittings. I have two people give different opinions one was a bent push rod, I checked the valve clearance they are all to the manual specs. The other who has worked on these machines said that the fuel lines could have a small wear hole that would cause it to suck air. I would think with the high pressure fuel would leak out of the hole. He said he has changed many of the lines. I am at a loss as to what to do. If the fuel lines could cause this I will replace them. The machine is not near any diesel repair shops and would have to be transported. Thank you in advance Bill

I had a 584 running rough, sputtering like it wasn't getting fuel and there was a pinhole sucking air but fuel was not running out as far as we could see. We took the line off and had a new one made and everything was fine.