Namely, a bad injector, static timing not correct, fuel injection pump malfunction. Supposedly if cyl.6 is starved of fuel the problem stops, it should run much better, not perfect but better. If it does run better, i'd start to suspect the injector (you can swap it with another cyl to see if the problem follows. Search: 12 Valve Cummins Injection Pump Timing Pin. h: Starting System: Electrical Starting Motor 12V/24V: Lowest Starting Temp This CAPS pump was a computer controlled injection pump, with individual fuel lines to each injector It has been completely rebuilt with Bosch parts and Calibrated on Certified Bosch test equipment Secure PayPal.