There are 2 main possible causes of such engine behavior: the ME itself and Nabtesco.
- Check ME injectors and fuel injection pumps. If their running hours already high or you using low grade fuel, your fuel system components might be worn. In this case, at low RPM fuel pumps & injectors cant ensure proper fuel supply and atomization. Hence, higher fuel rack scommand required to keep engine running. Replace / overhaul them.
- Nabtesco governor feedback potentiometer may be faulty. It’s lifetime is 5 years and if your’s is older it is advised to check/replace it.
Checks are easy:
- Navigate to tenkey 332 - GOVERNOR POTENTIO. SIGNAL in the Nabtesco console.
- On the immobilized engine, switch control to ECR and to SWITCh
- Adjust the setpoint for governor by pressing the Increase button once at the time . Every time the Increase button pressed, the tenkey 332 value increases and stays stable. Go therough the whole range of tenkey 332 values (9.65 to 9.98). If during adjustement you noticed unusual fluctuations of tenkey 332 value, this means your potentiometer is faulty and must be replaced. Normally, it must be stable after you depressed the button. Request one or call a technician.