M11 – Engine Runs Rough or Misfires

Symptom Tree  

Condition occurs only at idle

Refer to the Engine Runs Rough at Idle symptom tree.

 

Engine is operating at low ambient temperature

Check the winterfront, shutters, and under-the-hood air. Use under-the-hood intake air in cold weather. Refer to Procedure 101-015 (Operating the Engine) in Section 1.

 

Electronic fault codes are active

For instructions on how to read active fault codes, refer to Procedure 101-007 (Operating the Engine) in Section 1. If fault codes are active, contact a Cummins Authorized Repair Facility.

 

Fuel leak

Check the fuel lines, fuel connections, and fuel filters for leaks. Check the fuel lines to the supply tanks. Refer to the OEM service manual.

 

Fuel grade is not correct for the application or the fuel quality is poor

Operate the engine from a tank of high-quality fuel. Refer to Procedure 018-002 (Fuel Recommendations and Specifications) in Section V.

 

Air in the fuel system

Check for air in the fuel system. Tighten or replace the fuel connections, fuel lines, fuel tank standpipe, and fuel filters as necessary.

 

Fuel inlet restriction

Check for fuel inlet restriction. Contact a Cummins Authorized Repair Facility.

 

Engine mounts are worn, damaged, or not correct

Check the engine mounts. Refer to the OEM service manual.

 

Overhead adjustments are not correct

Measure and adjust the overhead settings. Refer to Procedure 003-004 (Overhead Set) in Section 5.

 
Contact a Cummins Authorized Repair Facility

Last Modified:  19-Nov-2004