What's the reason for a diesel engine not being able to restart after stalling?

[Trevor]

Main reason is that the engine temperature is too low. As long as the engine is kept warm and the biting cold wind is prevented from blowing directly into the engine compartment, the failure to start can be avoided. Specific information is as follows: 1. Parking precautions: When parking in winter, pay attention to the direction of the front of the car. It is best to point the front of the car towards a building, using the building to block the wind and prevent the engine from becoming too cold due to the cold wind. When parking at night, you can point the front of the car towards the direction of the rising sun, so that the first rays of sunlight in the morning can shine on the front of the car, helping the engine to warm up. This makes starting the car much easier. 2. Extended information: If the engine stalls when shifting gears, it may be due to the idle speed being too low at the time, or the idle cut-off valve not being tightened properly, or it could be caused by shifting into too high a gear, or the oil-gas separator being severely clogged.

[JulianAnn]

I've been repairing diesel vehicles for over a decade, and this kind of failure-to-start situation is extremely common. First check if the battery is low on power - if the horn sounds weak, that's usually the issue. Then listen to see if the starter motor is turning over. If it's clicking but can't crank the engine, it's mostly likely a fuel line blockage - diesel filters get dirty easily and can even develop wax buildup in cold weather. I once had a case where a customer used substandard diesel fuel and the impurities ruined the fuel pump. If the tank is nearly empty and sucks in air, you'll need to bleed the system before it can start. Other common causes include worn high-pressure fuel pump plungers or injector carbon buildup affecting ignition. The simplest emergency solution is replacing the filter and bleeding the system - if that doesn't work, you'll have to call a tow truck.

[OBrantley]

The most dreaded issue for transport in the Northeast during winter! Last week at -20°C, my truck just wouldn't start. If a diesel engine fails to start after shutting down, it's 90% likely frozen. Regular No. 0 diesel crystallizes at 0°C, so you must switch to -35 grade. If a few glow plugs are faulty, starting becomes difficult too – when turning the key to ON, if the dashboard glow plug light doesn't stay lit for at least 10 seconds, there's definitely a problem. Air in the fuel line is also troublesome; you'll need to loosen the vent screw on the diesel filter and manually pump the primer until no bubbles appear. Remember to replace the diesel filter during every maintenance, otherwise impurities clogging the injectors will cost you even more.

[SanGage]

From a mechanical principle perspective, diesel engine starting requires three conditions: sufficient rotational speed, high temperature in the cylinder, and fuel atomization. If the engine fails to start after shutdown, first check whether the starter reaches above 200 rpm. If the speed is normal but the engine doesn't fire, focus on checking the glow plug resistance value (normal range 0.5-1 ohm) and fuel injection timing. There was a case where the common rail system pressure was insufficient: normally requiring above 180 bar, but only 80 bar was measured. Disassembly inspection revealed a ruptured diaphragm in the fuel transfer pump. A failed crankshaft position sensor can also cause the ECU to not inject fuel, which requires reading fault codes with a diagnostic computer.