This post is designed to give a basic overview of modern Toyota Diesel engines and their commonly troublesome components: How does a Diesel engine work? Firstly Diesel is not as flammable as Petrol. Diesel engines don’t have spark plugs to ignite the fuel, but to bring about combustion they require heat. If you put your finger over the end of a foot pump and pump it, your finger will become hot. This is due to compression of the air trapped inside the pump (the air molecules have less space to m