Fuel and Combustion Quiz

A slightly lean fuel mixture offers good fuel economy and low exhaust emissions.

• True

• False

______ ratio is the chemically correct air-fuel ratio necessary to achieve complete combustion of the fuel and air mixture.

Lead was used in petrol to:

• increase catalytic converter efficiency.

• boost the octane rating.

• reduce vapour lock.

• prevent fuel line freezing.

All of these are advantages of electronically controlled fuel-injection over mechanical-injection systems, EXCEPT:

• continuous air-fuel adjustments are possible.

• reduced emissions are achieved.

• fuel is delivered in a continuous stream.

Which type of gauge reads 101 kPa (14.7 psi) at sea level?

• Absolute pressure

• Constant pressure

• Actual pressure

• Hydro pressure

Which of these describes when the air-fuel mixture spontaneously ignites before the spark plug fires?

• Detonation

• Advanced ignition

• Spark advance

• Pre-ignition

For petrol to burn properly, it must be mixed with the right amount of:

• carbon.

• air.

Getting rid of exhaust gases is as critical as getting air into the engine.

• True

• False

Petrol engines use fuel delivery to control engine speed.

• True

• False

The heated air intake system, found on carburetted and throttle-body injection systems, is used to ensure that fuel does not:

• A. vaporise.

• B. collect on the cold intake manifold.

• C. turn to gel when cold.

• D. freeze.