Fault Diagnosis Technique of Diesel Fuel Injection Pump
Posted: 2014-11-17 00:21:37 Hits: 1819
It’s difficult to judge intuitively the malfunction of high pressure pump during the working of diesel engine. In order to make beginner and personal with certain basic technique improve a lever to rule out the failure quickly, accurately and effectively, five exclusive methods are particularly introduced here for rapid troubleshooting.
1. Sounding. “Echo-meter” (not the device used for patient) can be used in the idling work of engine to touch large screwdriver and listen to the change of voice. It states too large amount of oil or too early fuel injection time if there is large knocking sound. It’s just the opposite if there is no knocking sound, and only continuous indistinct sound.
2. Temperature sensing. Keep the engine idle running for 10 minutes after starting, and then check the temperature of each exhaust pipe of cylinder. If the temperature of a certain cylinder is higher than others, it states the oil mass of this cylinder may be larger. If the temperature is lower, it shows that this cylinder works badly with smaller oil mass.
3. Pulsating. Hold each cylinder of high pressure oil pipe and sense the pulsating condition of fuel supply of high pressure oil pipe. It says the fuel supply is larger if the pulsating is large, whereas it indicates that fuel supply is smaller.
4. Oil cutting off. When the diesel engine reach the normal working temperature, make it idle running. Then cut off the oil way of each cylinder’s high pressure oil tube, letting the oil spray outside. Under normal circumstance, the rotating speed and sound of engine should have obvious change while a certain cylinder is being cut off. It illustrates that this cylinder has poor operation if there is no obvious change. This way can also be used to judge the failure of engine’s black smoke. It shows the fuel injector of this cylinder locked or atomization is bad after cutting off the oil line of certain cylinder and black smoke disappearing.
5. Color observation. For normal work of diesel engine, the color of waste gas discharged by diesel engine should be light gray, or dark gray under increased load. If the engine exhausts black smoke, white or blue smoke, it heralds that there are different faults in the engine fuel system. Black smoke means that the diesel mixture doesn't get full combustion due to blocked air filter, too late fuel supply, etc. White smoke means the diesel engine is too cold or there is water in diesel fuel or the mixture doesn’t burn at all. Blue smoke states that there is fuel entering into the cylinder and burn the fuel oil.
All in all, you can apply the above five ways together for a better effect. Of course, the specific diesel engine fault parts should be determined comprehensively. For example, if a certain cylinder is judged to work badly, you should check whether there is blockage or air in high pressure oil line, or whether the valve clearance is appropriate, etc. Anyway, flexible application of the above methods can achieve better effect.
1. Sounding. “Echo-meter” (not the device used for patient) can be used in the idling work of engine to touch large screwdriver and listen to the change of voice. It states too large amount of oil or too early fuel injection time if there is large knocking sound. It’s just the opposite if there is no knocking sound, and only continuous indistinct sound.
2. Temperature sensing. Keep the engine idle running for 10 minutes after starting, and then check the temperature of each exhaust pipe of cylinder. If the temperature of a certain cylinder is higher than others, it states the oil mass of this cylinder may be larger. If the temperature is lower, it shows that this cylinder works badly with smaller oil mass.
3. Pulsating. Hold each cylinder of high pressure oil pipe and sense the pulsating condition of fuel supply of high pressure oil pipe. It says the fuel supply is larger if the pulsating is large, whereas it indicates that fuel supply is smaller.
4. Oil cutting off. When the diesel engine reach the normal working temperature, make it idle running. Then cut off the oil way of each cylinder’s high pressure oil tube, letting the oil spray outside. Under normal circumstance, the rotating speed and sound of engine should have obvious change while a certain cylinder is being cut off. It illustrates that this cylinder has poor operation if there is no obvious change. This way can also be used to judge the failure of engine’s black smoke. It shows the fuel injector of this cylinder locked or atomization is bad after cutting off the oil line of certain cylinder and black smoke disappearing.
5. Color observation. For normal work of diesel engine, the color of waste gas discharged by diesel engine should be light gray, or dark gray under increased load. If the engine exhausts black smoke, white or blue smoke, it heralds that there are different faults in the engine fuel system. Black smoke means that the diesel mixture doesn't get full combustion due to blocked air filter, too late fuel supply, etc. White smoke means the diesel engine is too cold or there is water in diesel fuel or the mixture doesn’t burn at all. Blue smoke states that there is fuel entering into the cylinder and burn the fuel oil.
All in all, you can apply the above five ways together for a better effect. Of course, the specific diesel engine fault parts should be determined comprehensively. For example, if a certain cylinder is judged to work badly, you should check whether there is blockage or air in high pressure oil line, or whether the valve clearance is appropriate, etc. Anyway, flexible application of the above methods can achieve better effect.
