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Jackie Dempsey
Jackie Dempsey,
Category: Medium and Heavy Trucks
Satisfied Customers: 32
Experience:  Diesel Technician at Cummins Pacific
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M11 cummins misssing, it idles fairly well but when I speed

Customer Question

m11 cummins misssing
JA: Thanks. Can you give me any more details about your issue?
Customer: it idles fairly well but when I speed it up it has a definite miss
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Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Customer: replied 1 year ago.
How do I get my answer?
Expert:  Jackie Dempsey replied 1 year ago.

Goodmorning! i am more than happy to assist you with your question today. Can you please tell me if this engine is an M11 Celect or Celect plus? Also, is there a check engine light present?

Customer: replied 1 year ago.
1995 M11 330E model engine
Customer: replied 1 year ago.
I dont see anything on celect or celect plus
Expert:  Jackie Dempsey replied 1 year ago.

Thank you for that information, are there any check engine lights present on the dash?

Expert:  Jackie Dempsey replied 1 year ago.

The symptoms described sounds to me like a fuel system problem, however please keep in mind it is difficult to diagnose via the internet, but I will do my best! I would like to inquire as to what (if any) trouble shooting steps you have taken at this point? I would recommend checking to ensure there is no air in the fuel system, no visible fuel system leaks, verify that the oil level is within spec as well. I have seen a few different issues result as the cause of a miss on this particular engine. However in my experience it does usually turn out to be an injector issue

Expert:  Jackie Dempsey replied 1 year ago.

If by chance you have verified that the fuel system is working properly, the next most common problem I have seen is the cam sensor on these units. Not the most fun to change I will admit, however very possible. Due to the older style engine it may not be the easiest to diagnose without Cummins specific diagnostic equipment. If appropriate I would also advise to bring it into a Cummins facility so they may connect Insight and verify the operations of the engine internally with the computer. You can find your local Cummins distribution center by logging into or by calling 1 800 Diesels and a rep should be able to assist you. I hope that I have been able to shed some light on your issue at hand. If you have any further questions my name is ***** ***** I will gladly assist you. Please do not forget to rate my service today. Take care

Expert:  Jackie Dempsey replied 1 year ago.

I would like to also mention the best way to check for air in the system on these units is to hookup a sight glass to the inlet line of the fuel system and verify there are no bubbles, if bubbles are present you have air in the lines. Once again I hope I have been of assistance, please let me know if I can help further ;)

Expert:  Jackie Dempsey replied 1 year ago.

Hello there! I just wanted to check back in to see if you had any further questions? If so please let me know. Thank you