- Insufficient low idle speed setting
- Low fuel pressure
- Problem with driven equipment
- Problem with the governor
- Low quality fuel
Insufficient Low Idle Speed Setting
Adjust the low idle speed setting.
Ensure that there is fuel in the fuel tank. Look for leaks or faulty bends in the fuel line between the fuel tank and the fuel transfer pump. Check for air in the fuel system. Refer to Troubleshooting, "Air In Fuel" for more information. Ensure that the fuel filters are clean. Check the fuel pressure. The fuel pressure at the outlet of the fuel transfer pump must be a minimum of 200 kPa (29 psi) at full load speed. If the pressure is lower than the minimum, check the fuel transfer pump. Also check the fuel pressure regulating orifice.
Check the driveline for free movement. Disconnect the PTO drives or remove the PTO drives. Remove engine accessories and inspect engine accessories that may lock up the engine. The following components should be inspected:
- Air compressor
- Power steering pump
- Engine oil pump
- Hydraulic oil pump
Ensure that the governor is operating properly. If a problem with the governor is suspected, refer to Troubleshooting, "Governor Instability". If the problem can not be resolved, remove the governor and bench test the governor. If the governor can not be adjusted properly during the bench test, repair the governor or replace the governor. Bench test the repaired governor. If the governor must be replaced, bench test the new governor. Refer to Service Manual, SENR6454, "3114, 3116 & 3126 Engine Governors".
Check the API. Refer to Troubleshooting, "Fuel Quality".