Troubleshooting Automatic Flameout of Isuzu Diesel Engine
Posted: 2014-10-13 01:07:15 Hits: 1554
Symptom: The diesel engine (equipped with VE distributor pump) on a NHK notchback manufactured by Jiangxi Isuzu has good starting performance and it is quite normal when cooling. However, the engine losses its power gradually and even has flameout after running for a period of time.
Fault diagnosis: Burning machine oil and smoking do not exist in engine. The engine has slight channeling gas. Nozzle has good atomization without drip or being stuck. Fuel delivery meets the requirement under the different conditions of oil pump. There is good sealing existing between transmission shaft and oil seal. Low-pressure oil-way is quite smooth, having no air leakage and oil leakage. It is found that the temperature on pump body is ultrahigh after engine stopping automatically. Therefore, it can be judged that oil pump has obstacles on oil return. When checking oil return solenoid valve of oil pump, oil return holes are blocked up by dirties.
Trouble removal: Using a fine iron wire stabs oil return holes so that oil return holes become smooth again. Use gasoline to clean oil return holes completely. Then reinstall the oil return solenoid valve. Temperature on pump body is always normal after engine running for a long time. Power shortage and flameout do not happen again.
Fault analysis: Normally, high-speed components inside oil pump will produce amount of heat for rubbing each other. Most of heat depends on fuel returning to fuel tank through oil return holes to be cooled. When oil return of oil pump is blocked, heat on pump body cannot be transmitted, which resulting in temperature on pump rising sharply. Viscosity of fuel is lowered obviously, reducing oil supply of oil pump in proportion and leading to above fault.
Fault diagnosis: Burning machine oil and smoking do not exist in engine. The engine has slight channeling gas. Nozzle has good atomization without drip or being stuck. Fuel delivery meets the requirement under the different conditions of oil pump. There is good sealing existing between transmission shaft and oil seal. Low-pressure oil-way is quite smooth, having no air leakage and oil leakage. It is found that the temperature on pump body is ultrahigh after engine stopping automatically. Therefore, it can be judged that oil pump has obstacles on oil return. When checking oil return solenoid valve of oil pump, oil return holes are blocked up by dirties.
Trouble removal: Using a fine iron wire stabs oil return holes so that oil return holes become smooth again. Use gasoline to clean oil return holes completely. Then reinstall the oil return solenoid valve. Temperature on pump body is always normal after engine running for a long time. Power shortage and flameout do not happen again.
Fault analysis: Normally, high-speed components inside oil pump will produce amount of heat for rubbing each other. Most of heat depends on fuel returning to fuel tank through oil return holes to be cooled. When oil return of oil pump is blocked, heat on pump body cannot be transmitted, which resulting in temperature on pump rising sharply. Viscosity of fuel is lowered obviously, reducing oil supply of oil pump in proportion and leading to above fault.
