Technician A says that injector nozzles are either opened by the high-pressure pulse from a distributor pump or electrically by the computer on a common rail design. Technician B says that indirect injection (IDI) occurs directly into the combustion chamber. Who is right?

Question

Quizplus · Accepted Answer

Technician A is correct because injector nozzles can indeed be opened either by a high-pressure pulse from a distributor pump in older diesel injection systems or electrically by the computer in modern common rail designs. Technician B is incorrect because indirect injection (IDI) does not inject fuel directly into the combustion chamber; instead, it injects fuel into a pre-chamber or swirl chamber, from which it then enters the combustion chamber. Direct injection (DI), not IDI, occurs directly into the combustion chamber.

Technician a Says That Injector Nozzles Are Either Opened by the High-Pressure