When it is cold out, the fuel pump serves a very important function in that it supplies the engine with enough pressure to fire off and keep running. Diesel fuel congeals as in the wiry as it gets cold, making fuel more viscous. A functioning fuel pump is necessary to deliver low-pressure, high-volume fuel even this fuel has congealed into something as viscous as molasses. This pressure is usually somewhere between 35-65psi for most gasoline engines and any large drop in this pressure can cause hard starting or engine misfires.
A common problem when it gets cold outside is fuel line freezing; this blockage can prevent fuel from going to the pump. When this happens, the fuel pump may have a hard time providing adequate fuel and the vehicle will take longer to crank before it starts or fail to start all together. Winter fuel additives or antigel additives can be used to prevent fuel from freezing and ease the load on the fuel pump in winter. These additives function by reducing the fuel's gel point, ensuring easier flow even at lower temperatures.
Besides that the fuel pump has to work harder because the output of battery power is decreased during cold weather. This has the potential to affect power being supplied to the fuel pump, which typically needs about 12 volts in order to do its job as well as it can. This prevents the pump from generating enough pressure to start. A recent automotive survey from 2020 suggested that 20% of cold weather no-starts are related to the fuel system, with many times indicating the load on the poor old fuel pump.
Additionally, cold weather may result in condensation inside the fuel tank resulting in water building up and mixing with the fuel. If the pump cannot supply fuel to the engine, it may fail to start or stall out once it does. In addition, maintaining a higher fuel level in the tank — about half full in cold weather — will reduce the risk of any condensation forming and ensure that the fuel pump has adequate flow.
As noted by Elon Musk, "Performance in adverse environments is a true test of engineering." The cold weather is especially hard on the fuel pump and it is a good reminder for proper maintenance.
You can remove and replace your fuel pump for a new compatible one to keep you driving through winter really visit Fuel Pump for reliable quality components that can stand up to those cold conditions, consistently delivering the optimal amount of fuel.