Attention: TDR Forum Junkies 
A buddy transplanted a Cummins into a 4-door GM dually. I was checking it out yesterday, and he asked if I could help him figure out why one cylinder seems to be dead. Being a 1st gen owner, I'm not much help to him on his P-pump, but here's what I can tell you:
He started it and it was obviously "loping" like it was missing a cylinder. By the way, he says it will still outrun his dad's 'stroke as is.
While it was running, he cracked open the fuel line at the injector on #3. Fuel leaked, but the sound of the engine did not change. He cracked open #2 next. There was a change in the engine's sound/smoothness to indicate it was not firing. He has already replaced the #3 injector with a new one, with no improvement. He has swapped the new injector with an injector from another cylinder - no improvement. Then he swapped (with another cylinder) what he called a "regulator" which is located at top of the pump where the #3 fuel line attaches. Still no change. In my mind, the injection pump must be at fault internally. There was a noticeable difference in the pressure of the leaking fuel as he cracked the lines, with less pressure at #3.
Any ideas of what could be wrong? He is hesitant to pay the bucks to have the pump rebuilt (if necessary) at the local shop. He's interested in talking to someone else who could do the fix. I'd appreciate any help/experience you guys could pass on.
Fitz
He started it and it was obviously "loping" like it was missing a cylinder. By the way, he says it will still outrun his dad's 'stroke as is.
While it was running, he cracked open the fuel line at the injector on #3. Fuel leaked, but the sound of the engine did not change. He cracked open #2 next. There was a change in the engine's sound/smoothness to indicate it was not firing. He has already replaced the #3 injector with a new one, with no improvement. He has swapped the new injector with an injector from another cylinder - no improvement. Then he swapped (with another cylinder) what he called a "regulator" which is located at top of the pump where the #3 fuel line attaches. Still no change. In my mind, the injection pump must be at fault internally. There was a noticeable difference in the pressure of the leaking fuel as he cracked the lines, with less pressure at #3. Any ideas of what could be wrong? He is hesitant to pay the bucks to have the pump rebuilt (if necessary) at the local shop. He's interested in talking to someone else who could do the fix. I'd appreciate any help/experience you guys could pass on.
Fitz
