1. Because they lack an ignition source (i.e. magnetos and spark plugs), diesels incorporate glow plugs for cold starting. Heat from compressed air ignites the fuel-air mixture.
2. Diesels must use high-pressure fuel injector nozzles to pump fuel directly into the cylinders. The injector has to be able to withstand the temperature and pressure inside the cylinder and still deliver the fuel in a fine mist.
