Truck Repair: N 14 Injector adjustment, mileage engine, fuel pumps

Question
Hi Cliff,
I try to do most of my own work but have heard from Cummins mechanics that trying to set the injectors on a higher mileage engine (1997 N14 plus with 440,000 miles) could be trouble because when tightening the plunger, and then backing it out, can cause the part that has carbon buildup to become stuck and then it could misfire. Is this true? Or can I safely adjust them without worry.
Thanks, Will

Answer
Yes it is true but you can get injector flush & run it through the fuel system before you adjust overhead & it will be fine.You hook a fuel line to the suction side of the filter & MUST hook up return line to return fuel back to the flush can.The Celect fuel pumps flow maximum fuel pressure at all times & will empty the flush out in seconds.Run the flush through the engine for at least an hour,let it set overnight & run overhead when it is cool(140 degrees or less).