EFI

Question 1

The engine ECU always determines the proper fuel injection volume based on the signals from
various sensors

Answer 1

TRUE

Question 2

The check valve of the fuel pump closes to maintain the remaining pressure in the fuel line when
the fuel pump is stopped

Answer 2

TRUE

Question 3

The pressure regulator of recent models constantly controls the fuel pressure at higher pressure
against the intake manifold pressure.

Answer 3

FALSE

Question 4

The pulsation damper absorbs the fuel pressure pulsation in the fuel line.

Answer 4

FALSE

Question 5

The engine ECU turns on the circuit opening relay and the fuel pump operates while the ignition
switch is at IG position.

Answer 5

TRUE

Question 6

The STA signal is input in the engine ECU and the fuel pump operates while the ignition
switch is at ST position.

Answer 6

FALSE

Question 7

The NE signal is input in the engine ECU while the engine is running, and the fuel pump operates
continuously.

Answer 7

TRUE

Question 8

If the engine is stalled, the fuel pump is stopped because the NE signal is not input in the engine
ECU even if the ignition switch is at IG position.

Answer 8

TRUE

Question 9

The basic injection duration is determined by the accelerator opening angle and the engine speed.

Answer 9

TRUE

Question 10

The corrective injection duration is calculated from the engine condition detected by various
sensors

Answer 10

TRUE

Question 11

Actual injection duration = Basic injection duration + Corrective injection duration.

Answer 11

TRUE

Question 12

The injection duration becomes longer by the warm-up enrichment because the fuel is difficult to
be vaporized during a cold engine.

Answer 12

TRUE

Question 13

During engine starting.

Answer 13

TRUE

Question 14

After engine warm-up (Coolant temperature: more than 50°C (122 °C)).

Answer 14

TRUE

Question 15

During correction of acceleration enrichment and power enrichment

Answer 15

FALSE

Question 16

During the fuel cut-off control

Answer 16

TRUE

Question 17

When the output from the oxygen sensor is 0 V (lean) more than 15 seconds

Answer 17

FALSE

Question 18

The acceleration is detected by the vehicle speed sensor.

Answer 18

FALSE

Question 19

For the acceleration enrichment, the fuel increases greatly during the start of the
acceleration and is gradually reduced thereafter until the increase has ended

Answer 19

TRUE

Question 20

The more rapid acceleration is, the smaller the injection volume increases.

Answer 20

FALSE

Question 21

The acceleration is detected by the crankshaft position sensor and camshaft position sensor.

Answer 21

FALSE