AMT Engine Fuel Metering Systems 2

Question 1

What is the primary function of an accelerator pump in a float-type carburetor?

Accepted Answer

Provide extra fuel during rapid throttle opening to prevent a lean mixture

Answer

The accelerator pump delivers an extra shot of fuel when the throttle is opened quickly, preventing a momentary lean mixture that could cause engine stumble.

Question 2

In a pressure-injected carburetor, the fuel control unit meters fuel based primarily on which parameter?

Accepted Answer

The differential pressure between impact air and venturi suction

Answer

Pressure-injected carburetors use the differential between impact (ram) air pressure and venturi suction to meter fuel flow proportional to airflow.

Question 3

Which component in a continuous-flow fuel injection system controls fuel distribution to individual cylinders?

Accepted Answer

Flow divider (fuel manifold valve)

Answer

The flow divider (manifold valve) receives metered fuel from the fuel control unit and distributes it equally to each cylinder's injector nozzle.

Question 4

What is the purpose of the idle cut-off position on a mixture control?

Accepted Answer

Stop fuel flow to shut down the engine cleanly

Answer

Moving the mixture control to idle cut-off stops fuel flow to the engine, allowing shutdown by fuel starvation rather than ignition cutoff, which burns residual fuel and prevents after-firing.

Question 5

A carburetor's economizer system (power enrichment valve) is designed to:

Accepted Answer

Enrich the mixture at high power settings to prevent detonation and overheating

Answer

The economizer (power enrichment valve) opens at high power settings to richen the mixture, providing cooling and preventing detonation.

(AMT) Aviation Maintenance Technician Practice Test

(AMT) Aviation Maintenance Technician Practice Test

AMT Engine Fuel Metering Systems 2