Which of the following is delivered to the injector?

Prepare for the Engineman EN A School Test 1. Utilize flashcards and multiple choice questions with detailed explanations to boost confidence and readiness for the test.

Injectors are designed to atomize fuel and deliver it into the combustion chamber, and that requires fuel at very high pressure. The fuel pump (or rail system) raises the fuel pressure to a level high enough to force fuel through the tiny nozzle openings in the injector, creating a fine spray at the precise moment of injection. If fuel were supplied at low pressure, it wouldn’t atomize properly and wouldn’t reach the cylinder with enough energy for reliable ignition and combustion. Lubricating oil stays in its own circuit to lubricate moving parts and isn’t used to feed the injector, while compressed air isn’t the medium that drives the injector in a standard diesel system. So the fluid delivered to the injector is high‑pressure fuel.