Question 1

A vehicle has been 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.

Question 2

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 because the inertia switch, designed to cut off fuel supply in the event of a collision, indeed has a reset button that must be pressed to restore fuel pump operation. Technician B is incorrect because the inertia switch is triggered by a physical impact or collision, not by the ABS control module.

Question 3

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

A defective fuel pump relay can prevent voltage from reaching the fuel pump, causing a no start/no fuel pressure condition.

Question 4

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 5

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

Accepted Answer

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

Question 6

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

Technician B is correct because using the wrong adapter can cause a good gas cap to fail the test. Technician A is incorrect because the tester does not apply twenty inches of vacuum; it typically applies pressure to check for leaks.

Question 7

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

Accepted Answer

Fuel systems that operate within the 35 to 50 psi range typically draw between 4 to 9 amps of current, which aligns with the operational requirements of many automotive fuel pumps.

Question 8

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 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. Instead, it would cause a reduction in fuel flow to the engine, potentially leading to performance issues while the engine is running. Leaking injectors, a leaking fuel pump check valve, and a leaking fuel pressure regulator could all lead to a loss of fuel pressure when the engine is turned off.

Question 10

The fuel strainer is sometimes referred to as a ____________________.

Accepted Answer

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

Question 11

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

Technician A is correct because many modern vehicles use a fuel rail pressure sensor to monitor fuel pressure and control the fuel pump output via pulse-width modulation. Technician B is also correct because late-model vehicles often have fuel pumps controlled by the PCM using inputs from the CAN bus and other sensors.

Question 12

Fuel pumps should be tested for ____________________ and ____________________.

Accepted Answer

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

Question 13

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 14

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 pump...

Question 15

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

Accepted Answer

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

Question 16

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 17

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

Accepted Answer

The answer of If twenty inches of vacuum is applied...

Question 18

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

Accepted Answer

Hard starting can occur due to a loss of residual fuel pressure immediately after engine shutdown, as the fuel system may struggle to deliver the necessary fuel pressure to start the engine efficiently next time.

Question 19

In Chrysler EFI systems, the ASD relay (automatic shutdown)controls the power to the ______.

Accepted Answer

In Chrysler EFI (Electronic Fuel Injection) systems, the ASD (Automatic Shutdown) relay controls the power to the fuel pump, injectors, and the positive primary coil terminal, making all the provided options correct.

Question 20

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

Accepted Answer

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

Quiz 29: Fuel Delivery Systems