Maintenance method of diesel engine EFI 1. The engine won't start/it's difficult to start.
Possible reasons:
1, poor oil path or gas in oil, insufficient oil inlet pressure of oil transfer pump.
2. The starting signal is lost, the starter circuit or starter is damaged, or it is not in neutral.
3, the cylinder leakage pressure is low.
4. Wrong valve timing.
5. Enter the thermal protection state.
6.ECU is not energized/battery voltage is insufficient
7, synchronization signal error
8. Oil injection failure or pipeline damage
Maintenance suggestion:
1. Connect the diagnostic instrument, read the fault code, and distinguish the circuit or oil circuit fault.
2, check the fuel circuit or engine oil circuit, check the intake and exhaust circuit.
3. Check whether the pressure limiting valve of the metering valve is damaged or stuck.
4. Check whether the oil pump can provide enough rail pressure.
5. Check whether the engine is in thermal protection state.
6, check whether the synchronization signal is correct
7. Please refer to the maintenance materials for specific maintenance methods and steps.
Second, limp home
Possible reasons:
1, the metering valve is too open or the pressure limiting valve is open.
2, crankshaft or camshaft sensor damage or short circuit, open circuit.
3.* * * The rail pressure sensor is damaged or the line is open or short-circuited.
4. The accelerator pedal sensor is damaged or the circuit is open or short.
Maintenance suggestion:
1. Connect the diagnostic instrument and read the fault code, which is used to distinguish the circuit or mechanical fault.
2. Check whether the pressure limiting valve is open, whether the metering valve is stuck and whether the opening is too large.
3. Check whether the rail pressure is consistent with the target rail pressure, and whether the line has short circuit and open circuit.
4, check whether the crankshaft and camshaft sensor signal is lost or line fault.
5. Check whether the accelerator pedal sensor is damaged or faulty.
6. Please refer to the maintenance manual for specific maintenance methods and steps.
Third, the engine emits black smoke.
Possible reasons:
1, poor atomization of the fuel injector and blockage of the dripping air intake system.
2. The valve leaks, and the valve timing is wrong.
3.EGR valve failure
4, rail pressure sensor signal drift
5. Intake pressure sensor fault or line fault.
6, temperature sensor signal error
Inspection method:
1. Connect the diagnostic instrument to read the fault code and make repairs according to the fault code.
2. Read whether the data flow of rail pressure sensor, intake pressure sensor and temperature sensor is correct and whether the intake system is blocked.
3. Replace or adjust the fuel injector.
4. Specific methods of treatment
Fourth, the engine power is insufficient.
Possible reasons:
1. The air intake system is blocked and the air intake is insufficient.
2. The pressure of the fuel system is insufficient, and the common rail pressure cannot be established.
3. Wrong valve timing.
4. Insufficient cylinder pressure
5, the temperature is too high, into the state of thermal protection.
Inspection method:
1. Connect the diagnostic instrument, and preliminarily distinguish between circuit fault and mechanical fault.
2, check whether the rail pressure is normal, high and low pressure oil return is normal, whether there is a blockage phenomenon.
3, check whether to enter the thermal protection state.
4. Check whether the intake pressure value is normal and whether the intake system is blocked.
5. Check whether the gas distribution phase is correct.
Diesel EFI 1 Position and function of each sensor. Water temperature sensor: (located on the engine outlet pipeline) measures the temperature of coolant, which is used for fuel injection quantity correction, torque correction, rail pressure correction and thermal protection.
2. Atmospheric pressure sensor: (The atmospheric pressure sensor is integrated in ECU) detects atmospheric pressure and measures altitude, which is used to control the correction of fuel injection parameters.
3. Fuel temperature sensor: It measures the fuel temperature (on the diesel primary filter or oil pump) and is used for fuel injection quantity correction, torque correction and thermal protection.
4. Camshaft position sensor: (When installed on the oil pump, the overhead camshaft on the instrument cover is installed on the valve cover) is used to determine the top dead center signal of 1 cylinder.
5. Crankshaft position sensor: (on the flywheel housing, beside the crankshaft pulley and on the engine block) is used to measure the engine speed and crankshaft angle.
6. Oil pressure sensor: (on the main oil passage of the engine) is used to measure the oil pressure.
7. Intake air pressure and temperature sensor: (behind the turbocharger of intake pipe) measures intake air volume and intake air temperature for fuel injection quantity correction and thermal protection.
8. Air flowmeter: (behind the air filter, on the intake pipe in front of the turbocharger) measures the amount of air entering the intake pipe to correct the fuel injection amount.
9. Accelerator pedal position sensor: Measure the pedal stroke (on the accelerator pedal) to reflect the driver's intention and use it for fuel injection calculation.
10. Knock sensor: It detects the combustion state of the engine (on the engine block) and accurately controls the pre-injection.
1 1, * * rail pressure sensor: measure the fuel pressure in the * * * rail pipe (on the * * rail pipe) to ensure stable temperature and pressure control.
12. Water content sensor: (installed on the coarse filter) detects the water content in the fuel and reminds the driver to be waterproof in time.
Diesel EFI excavator 1 Matters needing attention in use and maintenance. Perform regular maintenance according to the manufacturer's recommendations.
The manufacturer will provide maintenance suggestions, such as replacing the filter element 500h, and informing the agent service personnel to come for maintenance before 500h, so as to facilitate the agent service personnel to arrange the trip, which will not affect the normal use of the excavator, but also protect the engine on time, especially the air filter, diesel coarse filter, engine oil and engine oil filter. It is recommended to use the original factory accessories for coarse and fine filtration of diesel oil, and avoid using the accessories from the auxiliary factory. Don't use a filter element of several hundred yuan to cause the failure of fuel injector or high pressure oil pump. There are many examples that the use of non-original accessories has caused some huge losses and cannot be guaranteed.
Attention should be paid to the quality of diesel oil, impurity content, sulfur, moisture and acid value in fuel oil, which will cause corrosion and wear of injector. Even if the injector is treated with high wear-resistant coating technology, poor fuel quality will cause hidden dangers such as frequent filter element replacement, high maintenance cost and increased failure rate. If possible, an oil filter can be added to filter the diesel oil once before refueling, and the operator can empty the fuel filter element with oil-water separator.
2. The oil-water separator frequently drains water and frequently replaces the air filter.
It is recommended to replace two sets of air filters. Expose the replaced filter screen in the sun for a day and then blow it with an air compressor, so that it can be blown more cleanly. Every time you add fuel, you should visually inspect the oil quality, and if necessary, you can add the fuel coarse filter element yourself. It is recommended to use a slightly larger throttle. Don't turn down the throttle in order to save a few dollars, lest the engine load be high.
Friends who know the engine know that the engine running under heavy load is easy to cause incomplete combustion and carbon deposition. In fact, carbon deposition is the chief culprit leading to premature death of injectors. When the excavator enters the idle state due to automatic idle speed, it is suggested to lean on the handle lightly when working again, and then work after the engine runs at high speed, thus protecting both the engine and the hydraulic pump.
3. Use original spare parts and engine oil to be replaced.