Not to get offtrack but a 7.3 will start just fine in cold weather. Now if you have some bad parts such as a bad relay or glow plugs then all bets are off. But then this goes for any diesel engine that uses glow plugs, air heaters, or whatever else to aid in cold weather starts. Big engines don't need glow plugs because they have a lot more swept volume in relation to the surface area of the combustion chamber. This means that less of the heat generated in compression "leaks" away into the cold cylinder walls and head. This also explains why a 6.0 liter PSD needs glow plugs while a 5.9 liter Cummins does not. The most common sign of damaged glow plugs is a difficult start. Without properly functioning glow plugs, the combustion chamber may not reach the proper temperature to ignite the gasoline and start the engine in cold temperatures. Glow plugs should be checked if there are no problems with the gasoline or the battery. 2. Misfiring of the engine To start, a diesel engine requires the help of glow plugs. Spark plugs are not used in diesel vehicles because they do not produce enough heat for the mixture in a diesel combustion chamber. Cylinder compression is stronger in diesel engines, so they require more heat to ignite. Functionality: Glow plugs are essential for diesel engines to start in cold weather conditions. In cold weather, the air in the combustion chamber can be too cold to ignite the fuel, making it difficult or impossible for the engine to start. The glow plugs heat up the air in the combustion chamber, making it hot enough to ignite the fuel. . I’m sure they built the engine around them glow plugs. Many hours of dropping things and grazed knuckles. My 11 plate Fiesta I don’t even notice the light no matter how cold it is. 1. Glow Plugs and Block Warmers: On a chilly day, the vast majority of diesel engines can be started with glow plugs or block heaters. Glow plugs work by heating the internal combustion chamber, allowing for proper compression and, eventually, ignition. 2. Wait for the Glow Plugs to Warm Up: If the combustion chamber isn’t sufficiently heated Remove any covers that may be obstructing access to the glow plugs, and use the flashlight for additional illumination if necessary. Step 3: Disconnect the glow plug wires. Once all of the glow plugs have been located, disconnect any wires or caps attached to them. Step 4: Touch the negative terminal. Starting a cold diesel engine without glow plugs presents a unique set of challenges. The absence of glow plugs means the combustion chamber remains cold, making it difficult for the fuel-air mixture to reach its ignition temperature. Without the initial burst of heat, the glow plugs provide, the compression alone may not generate enough heat Functionality: Glow plugs are essential for diesel engines to start in cold weather conditions. In cold weather, the air in the combustion chamber can be too cold to ignite the fuel, making it difficult or impossible for the engine to start. The glow plugs heat up the air in the combustion chamber, making it hot enough to ignite the fuel.

how does a diesel engine work without glow plugs