M11 Series Engines – Engine Speed Surges at Low or High Idle

Symptom Tree  t066

This is symptom tree t066
Cause Correction

Electronic fault codes active or high counts of inactive fault codes

Refer to Section TF in the Troubleshooting and Repair Manual for CELECT™ Plus Systems, Bulletin 3666130, or Section TF in the Troubleshooting and Repair Manaul for CELECT™ Systems, Bulletin 3666084 for fault code troubleshooting.

 

Air in the fuel system

Check for air in the fuel system. Refer to Procedure 006-003.

 

Fuel level is low in the tank

Fill the supply tank. Refer to the OEM service manual.

 

Fuel inlet restriction

Check for fuel inlet restriction. Refer to Procedure 006-020.

 

Engine idle speed is set too low (electronically controlled fuel systems)

Verify the correct idle speed setting. Increase the idle speed with the idle increment switch or an electronic service tool. Refer to the appropriate electronic service tool manual.

 

Engine idle speed is set too low (mechanical fuel systems)

Adjust the fuel pump idle speed. Refer to Procedure 005-029.

 

Electronic control module (ECM) calibration is malfunctioning

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history for applicable fixes to the calibration stored in the ECM. Refer to the calibration history spreadsheet Click here to see ecm_calibration_rev_history.xls

on QuickServe® Online Internet Website or the INCAL™ calibration CD. Compare the calibration stored in the ECM with the engine rating and the Control Parts List (CPL), Bulletin 4021326 or 4021327. If necessary, recalibrate the ECM. Refer to the appropriate electronic service tool manual and Procedure 019-032 in the Troubleshooting and Repair Manual for CELECT™ Plus Systems, Bulletin 3666130, or in the Troubleshooting and Repair Manual for CELECT™ Systems, Bulletin 3666084.

 

Fuel drain line restriction

Check or replace the fuel lines, check valves, or tank vents as needed. Refer to Procedure 006-012.

 

Injector is malfunctioning (CELECT™ and CELECT™ Plus)

Perform the automated cylinder performance test. Replace injectors as necessary. Refer to Procedures 006-005 and 006-026.

 

Engine position sensor (EPS) or circuit is malfunctioning

Check the engine position sensor and circuit. Refer to Procedures 019-038 and 019-039 in the Troubleshooting and Repair Manual for CELECT™ Plus Systems, Bulletin 3666130, or in the Troubleshooting and Repair Manual for CELECT™ Systems, Bulletin 3666084.

 

Injector is malfunctioning (PT/STC)

Remove and check the injectors. Replace injectors as necessary. Refer to Procedure 006-026.

 

Automotive and variable speed (VS) governor idle speeds are set too close (STC engines only)

Adjust the automotive and VS idle speeds. Refer to Procedures 005-028 and 005-029.

 

PT fuel pump calibration is not correct

Remove the fuel pump. Check the calibration. Refer to Procedure 005-016 and the PT Fuel Pump Rebuild and Calibration Manual, Bulletin 3379084.

 

PT fuel pump is not assembled correctly

Check the fuel pump for correct assembly and installation. Refer to Procedure 005-016 and the PT Fuel Pump Rebuild and Calibration Manual, Bulletin 3379084.

 

Camshaft end clearance is excessive

Check the camshaft end clearance. Refer to Procedure 001-065.

 
Last Modified:  02-Feb-2007