fuel injection

Injecting fuel directly into the cylinders of an internal combustion engine, instead of by way of a carburettor. It is the standard method used in diesel engines, and is now becoming standard for petrol engines. In the diesel engine, oil is injected into the hot compressed air at the top of the second piston stroke and explodes to drive the piston down on its power stroke. In the petrol engine, fuel is injected into the cylinder at the start of the first induction stroke of the four-stroke cycle.