Engine Missing under load

[oldtymer]

I have a 2000 Dynasty with a Cummings 350 ISC. Approximately 1 hour after refueling at a truck stop, my engine develped a sever miss when climbing grades. It ran fine cruising level areas but would start to miss when it came to the next grade. No miss was present at speeds below 60 even when accelerating to reach highway speeds. The Cummings engine manual says this condition is caused by restricted fuel flow or air inleakage to the fuel system. I changed fuel filters with no improvement. A Cummings service center found bits of rubber partially blocking the check valve at the primary fuel filter. The cleaned out the debrie and the problem was solved. They stated the cause was likely a fuel line degrading. They were not able to replace my fuel line so I continued my trip. After approximately 400 miles, I pulled the check valve and found no new debrie. I have traveled approximately 1000 miles with no recurrance of this problem Has anyone else had to change fuel lines? The service center indicated they can fail at 10 years and should be replaced.

[Coma]

Quote:

Originally Posted by oldtymer I have a 2000 Dynasty with a Cummings 350 ISC. Approximately 1 hour after refueling at a truck stop, my engine develped a sever miss when climbing grades. It ran fine cruising level areas but would start to miss when it came to the next grade. No miss was present at speeds below 60 even when accelerating to reach highway speeds. The Cummings engine manual says this condition is caused by restricted fuel flow or air inleakage to the fuel system. I changed fuel filters with no improvement. A Cummings service center found bits of rubber partially blocking the check valve at the primary fuel filter. The cleaned out the debrie and the problem was solved. They stated the cause was likely a fuel line degrading. They were not able to replace my fuel line so I continued my trip. After approximately 400 miles, I pulled the check valve and found no new debrie. I have traveled approximately 1000 miles with no recurrance of this problem Has anyone else had to change fuel lines? The service center indicated they can fail at 10 years and should be replaced.

IMO you got your rubber when you fueled. Perhaps the fuel pump's hose was the one deteriorated.

[wa8yxm]

I would go with that too.. Used to have a van (Gasoline) which from time to time had bits of rubber in the needle valve on the carb (remember when engines had carbs)

Finally had to replace the fuel pump which was the source. That was fun. Did the job in the Farmington City (MI) Police Dept parking lot after a nice officer helped me get it off the main road.

[jdecastro]

I had the exact same problem on my 2000 ISC 315. It turned out to be neoprene check valve parts from the lift pump. Changed the pump and all is well. In my opinion it was caused by the new low sulphur fuel but who knows.