Fault Analysis on Diesel Engine Failure to Start
Diesel engine cannot start-1
Fault phenomenon: Deutz diesel engine, when the power switch is turned on and the diesel engine is started, the diesel engine rotates slowly, is weak, and cannot start.
Troubleshooting process: (Carry out the following troubleshooting steps based on the above situation)
A. Whether the battery is fully charged, and whether the power connector is in poor contact or loose;
B. Whether the oil transfer pump is damaged or stuck;
C. Eliminate blockage caused by mechanical failure of the diesel engine;
D. Check whether the oil line is blocked;
E. After removing the starter motor and inspecting it, I found that the teeth of the gear were chipped and the speed was slow and unbalanced.
Based on the above situation, replace the starter motor and check the oil supply of the oil circuit. After removing the air, start the diesel engine and return to normal.
Failure analysis: Due to the operator starting the engine too many times and for too long, the bearings at both ends of the motor rotor were severely worn, causing an internal ground short circuit, resulting in a voltage drop, insufficient motor output power, and making the diesel engine unable to start.
Diesel engine cannot start-2
Fault phenomenon: When the Deutz diesel engine is started, the motor runs normally, but the air in the fuel pipeline cannot be removed, making the diesel engine unable to start.
Elimination process: In the diesel engine oil circuit, diesel is sucked out of the fuel tank, passes through the oil pipe, enters the diesel coarse filter, then to the oil transfer pump, then to the fine filter, and finally enters the oil chamber of the unit pump. First check whether the oil pipes and joints are broken or leaking, then check whether the coarse filter and fine filter are blocked, whether the sealing gasket is flat when replacing the filter, and whether there is any air leakage or oil leakage. After checking that there are no problems above, check the diesel fuel pump and pressure limiting valve. It was found that the fuel delivery pressure of the fuel delivery pump was insufficient. After replacing the fuel delivery pump and removing the air, the diesel engine returned to normal. (You can use an intravenous drip method to determine whether there is an oil leak in the low-pressure oil line or a problem with the oil transfer pump and high-pressure oil line)
Failure analysis: By disassembling the oil transfer pump, it was found that the valve seat of the pressure limiting valve body was eccentrically worn, resulting in a reduction in oil supply pressure and making the diesel engine unable to start.
Diesel engine cannot start-3
Fault phenomenon: Turn on the power, turn the electric key, and start the diesel engine. It feels like the diesel engine has started, but after releasing the start button, the diesel engine stops again. Observe carefully that the moment you release the start button, the parking solenoid valve loses power (demagnetization) at the same time and returns to the parking position.
Cause analysis: The diesel engine can catch fire, which means there is no problem with the diesel engine fuel system, so we turn our attention to the electrical system. The working principle of the parking solenoid valve of the Deutz diesel engine is to energize and supply oil, and to cut off the supply of electricity and oil. Due to the loose thread, the parking solenoid valve loses power at the same time when the start button is released.
Solution: Arrange the loose wire connectors and tighten them so that they have good contact.
Diesel engine cannot start-4
Fault phenomenon: Turn on the power, turn the electric key, and start the diesel engine. It feels like the diesel engine motor operates normally, but the diesel engine never starts on fire and the exhaust pipe does not emit smoke.
Troubleshooting process: It was found that the parking solenoid valve was powered off and had no action. Sort out the lines and get back to normal.
Cause analysis: The diesel engine motor operates normally, but cannot catch fire, and the exhaust pipe does not emit smoke, which means that the diesel engine has basically no oil supply. The parking solenoid valve of the Deutz diesel engine is powered on and oil is supplied, and the power is cut off and the oil is cut off. Because the parking solenoid valve is always in a power-off and oil-off state, it cannot be started.
If it is winter, it may be that the diesel fuel rating is too high and the fuel cannot be supplied normally, causing the diesel engine to fail to start. Therefore, you should check whether any diesel oil has wax precipitation due to low temperatures, causing the fuel system to become clogged. In severe cases, some parts of the fuel system may be damaged. Therefore, the diesel grade should be appropriately selected according to the local temperature.
