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ASVAB · Ignition and Fuel Systems

What does a fuel injector do?

Reviewed by Jordan Morley, Editorial Lead at 247SimpleTests. Written by the 247SimpleTests Editorial Team from the official source material cited on every question.

Correct answer

Sprays a precise amount of fuel into the engine's intake or cylinder

  1. A Cools the fuel
  2. B Sprays a precise amount of fuel into the engine's intake or cylinder
  3. C Filters air
  4. D Stores fuel

Why this is the answer

A fuel injector sprays a precise, metered amount of fuel into the engine — into the intake port or directly into the cylinder — where it mixes with air for combustion. Modern engines use electronic fuel injection (EFI) controlled by the engine computer, which has largely replaced the older carburetor. Precise injection improves fuel efficiency, power, and emissions control. The injector's job is delivering the right amount of fuel at the right time. Understanding fuel injection versus the older carburetor system is common Auto Information content on the fuel-system topic.
Source: ASVAB Auto Information — Fuel Injection

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About this topic: Ignition and Fuel Systems

Ignition and fuel questions cover how spark plugs, coils and the firing order deliver a spark at the right moment, and how fuel injection, pumps and filters deliver fuel. Symptoms of a fault in each system are a favourite question type. This is one of 8 Auto Information questions on ignition and fuel systems, each with a full explanation on a single study page.

New to this exam? Our ASVAB exam guide explains the format, scoring, and how to prepare.

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