Examkin

Question

Difficulty: EasyFuel and Air Intake Systems

When an automotive engine is operating with a lean air-fuel mixture, which of the following conditions is present in the combustion chamber?

  1. A
    An excess of fuel relative to the amount of air
  2. An excess of air relative to the amount of fuelAnswer
  3. C
    Fuel entering the cylinder during the exhaust stroke
  4. D
    Air entering the cylinder exclusively during the compression stroke

Answer

An excess of air relative to the amount of fuel
The correct answer identifies that a lean air-fuel mixture contains too much air or not enough fuel relative to the ideal stoichiometric ratio. In gasoline engines, any ratio with more air than the standard 14.7:1 proportion is considered lean.

Step-by-Step Solution

1
Identify the standard terminology used to describe automotive air-fuel ratios.
The terms 'rich' and 'lean' describe deviations from the stoichiometric air-fuel ratio.
Understanding standard automotive definitions is necessary to determine mixture proportions.
2
Apply the definition of a 'lean' condition.
A lean mixture contains a higher proportion of air relative to fuel compared to the ideal stoichiometric balance.
A deficiency of fuel or a surplus of intake air creates a lean operating state.

Key Concept

Air-fuel mixture ratio terminology (rich vs. lean)
Estimated Time:45s
Rate this question

Topics

Fuel and Air Intake Systems

More questions from this topic