Recently, a Caterpillar cat340 excavator always has high water temperature and black smoke when digging
Cause of failure:
1 the oil pump and nozzle may be out of order
The abrasion of 2 hydraulic pump liner and valve plate will also lead to black smoke from the excavator and vehicle suffocation
3 diesel pump and supercharger are worn
4. The pressure and flow data of the hydraulic system do not match, which will also cause the excavator to emit black smoke and suffocate the vehicle
5. The power of the hydraulic system is greater than that of the engine, resulting in vehicle suffocation
Diagnostic steps:
1 first, check the working condition of the engine, and try to conduct cylinder by cylinder fuel cut-off test when the engine is running When the oil supply of a cylinder is cut off, if the engine speed decreases significantly, the black smoke decreases, and the knocking sound becomes weak or disappears, it indicates that the oil supply of the cylinder is excessive; If the engine does not change or the change is very small, it indicates that the fuel supply of the cylinder is too small; If the engine speed changes little and the black smoke disappears, it indicates that the spray quality of the cylinder injector is poor After finding out the faulty single cylinder, further check the cause of the fault, such as the condition of the fuel injection pump plunger pair of the cylinder, whether the sector gear fixing screw is loose and whether the plunger spring is broken If it is normal, the fuel injector can be disassembled and inspected, and a new fuel injector can be installed for comparison if necessary; If the fault disappears with a new injector, the original injector is faulty
2 if the fuel injection quantity of each cylinder is too large, open the governor cover and check whether the scale of the adjusting toothed rod moves too much into the fuel injection pump housing (the scale line should be equal to the rear end face of the fuel injection pump housing) If the diesel engine emits black smoke and a clear knocking sound can be heard in the cylinder, it indicates that the injection time is too early, and the injection timing should be calibrated correctly If the air filter is found to be blocked (the filter element is dirty) during inspection, it shall be cleaned and purged immediately
3 secondly, if the plunger tappet of the fuel injection pump is equipped with an adjusting screw, check whether the fuel injection timing of each cylinder is consistent
Sumitomo excavator emits black smoke and high water temperature. Troubleshooting:
1 first, check the quality of diesel oil used by excavator
2. Secondly, check the oil supply quantity of excavator diesel pump
3 also check whether the excavator air filter is blocked
4 adjust the excavator injector, replace the injector with poor atomization and calibrate the diesel oil pump
5 if the problem of black smoke from the excavator cannot be eliminated, check the hydraulic system of the excavator
