Question 1

A fuel system that runs at 35 to 50 psi should draw around _____ amps of current.

Accepted Answer

Fuel pumps that run at 35 to 50 psi typically draw around 4 to 9 amps of current.

Question 2

Technician A connects a fuel pressure gauge to the Schrader valve on the fuel rail. Technician B connects the gauge to the fuel lines by inserting a tee adapter between the fuel filter and the fuel rail. Who is correct?

Accepted Answer

Both Technician A and Technician B are correct because there are multiple valid methods to connect a fuel pressure gauge for diagnostic purposes. Technician A's method of connecting directly to the Schrader valve on the fuel rail is a common and straightforward approach. Technician B's method of using a tee adapter to insert the gauge between the fuel filter and the fuel rail is also a valid technique, especially in systems without a Schrader valve. Both methods allow for accurate measurement of the fuel pressure.

Question 3

Fuel pumps should be tested for ____________________ and ____________________.

Accepted Answer

The answer of Fuel pumps should be tested for ____________________...

Question 4

When a vehicle will not start because of no fuel delivery, the first check should be the ____________________.

Accepted Answer

The answer of When a vehicle will not start because...

Question 5

A restricted fuel filter will cause ____________________ than normal fuel pressure.

Accepted Answer

The answer of A restricted fuel filter will cause ____________________...

Question 6

On many vehicles, the ____________________ must be removed to replace the fuel pump.

Accepted Answer

The answer of On many vehicles, the ____________________ must be...

Question 7

Technician A says on some vehicles the fuel pressure is monitored by a fuel rail pressure sensor and the output of the fuel pump is controlled by the PCM through pulse-width modulation. Technician B says all fuel pumps on late-model vehicles are controlled by the PCM according to inputs received on the CAN bus and other specific sensors.Who is correct?

Accepted Answer

The answer of Technician A says on some vehicles the...

Question 8

A loss of residual fuel pressure immediately after engine shutdown could cause ______.

Accepted Answer

A loss of residual fuel pressure immediately after engine shutdown could cause hard starting, as there may not be enough fuel in the system to start the engine easily. It is unlikely to cause surging, loss of power at high speed, or excessive emissions as these issues are more likely related to ongoing issues with the fuel system during engine operation.

Question 9

Which of the following problems could NOT cause the fuel pressure to drops off quickly after the engine and ignition are turned off.

Accepted Answer

A restricted fuel filter would not cause the fuel pressure to drop off quickly after the engine and ignition are turned off. The other options (leaking injector, internally leaking fuel pump check valve, and internally leaking fuel pressure regulator) could all cause this issue.

Question 10

If twenty inches of vacuum is applied to the fuel pressure regulator while the fuel pump is running, the fuel pressure should _____.

Accepted Answer

Applying vacuum to the fuel pressure regulator decreases the fuel pressure because the regulator reduces pressure in response to vacuum to maintain the correct fuel-to-air ratio.

Question 11

If a vehicle is to be stored for several months, a fuel ____________________ should be added to the gasoline in the fuel tank.

Accepted Answer

The answer of If a vehicle is to be stored...

Question 12

A vehicle is being diagnosed with a low fuel pressure problem. A fuel pump current test reveals higher than normal current flow. Technician A says the vehicle may have a clogged fuel filter. Technician B says the fuel pump ground wire may be loose or corroded. Who is correct?

Accepted Answer

A clogged fuel filter can cause the fuel pump to work harder, leading to higher current flow. A loose or corroded ground wire would typically cause lower current flow, not higher.

Question 13

A pressure ____________________ can be used to connect a DMM (or lab scope) to the fuel system to measure fuel pressure.

Accepted Answer

The answer of A pressure ____________________ can be used to...

Question 14

In Chrysler EFI systems, the ASD relay [automatic shutdown] controls the power to the ______.

Accepted Answer

The ASD relay in Chrysler EFI systems controls power to the fuel pump, injectors, and the positive primary coil terminal, making all the options correct.

Question 15

Technician A says the inertia switch has a reset button that must be depressed for at least one second before the pump will operate again. Technician B says the inertia switch is triggered by the ABS control module. Who is correct?

Accepted Answer

Technician A is correct. The inertia switch does have a reset button that needs to be pressed for at least one second before the fuel pump will operate again. Technician B is incorrect in stating that the ABS control module triggers the inertia switch. The inertia switch is usually triggered by a sudden impact or vibration, such as in the event of a collision, that interrupts the electrical circuit to the fuel pump.

Question 16

A(n) ____________________ switch shuts off the fuel pump if the vehicle in involved in a collision or rolls over.

Accepted Answer

The answer of A(n) ____________________ switch shuts off the fuel...

Question 17

A no start/no fuel pressure condition is being diagnosed. When a test light is connected to the pump positive terminal, there is no voltage when the engine is cranked by the starter. What could cause this problem?

Accepted Answer

If there is no voltage at the fuel pump positive terminal when the engine is cranked by the starter, it is likely that the fuel pump relay is defective and not sending power to the pump. The neutral safety switch and fuel pressure regulator are not directly related to the fuel pump receiving power. A bad fuel pump ground could cause issues with the pump running, but would not prevent power from reaching the pump in the first place.

Question 18

An in-tank electric pump is usually the ____________________ type.

Accepted Answer

The answer of An in-tank electric pump is usually the...

Question 19

The fuel strainer is sometimes referred to as a ____________________.

Accepted Answer

The answer of The fuel strainer is sometimes referred to...

Question 20

Gas cap testing is being discussed. Technician A says the tester applies twenty inches of vacuum to the cap and measures its rate of leakage. Technician B says if the wrong adapter was used, the cap will fail the test even if it is good. Who is correct?

Accepted Answer

The answer of Gas cap testing is being discussed. Technician...

Quiz 29: Fuel Delivery Systems