Combustion in a diesel engine is achieved by a high compression-end pressure and temperature. The injector sprays diesel fuel into the combustion chamber at the correct moment, after which the mixture of air and fuel ignites spontaneously. During a cold start, the glow plug ensures preheating of the air in the combustion chamber. Several developments have made it possible to inject the fuel in a different way, such as the unit injector and common rail techniques.
