OBJECTIVES
After studying Chapter 24, the reader will be able to:
1. Prepare for ASE Engine Performance (A8) certification test
content area “C” (Fuel, Air Induction, and Exhaust Systems
Diagnosis and Repair).
2. Describe how to check an electric fuel pump for proper
pressure and volume delivery.
3. Explain how to check a fuel-pressure regulator.
4. Describe how to test fuel injectors.
5. Explain how to diagnose electronic fuel-injection problems.
6. Describe how to service the fuel injection system.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
PORT FUEL-INJECTION PRESSURE REGULATOR
DIAGNOSIS
• To test a vacuum-controlled fuel-pressure regulator,
follow these steps:
– Connect a fuel-pressure gauge to monitor the fuel
pressure.
– Locate the fuel-pressure regulator and disconnect the
vacuum hose from the regulator.
– With the engine running at idle speed, reconnect the
vacuum hose to the fuel-pressure regulator while
watching the fuel-pressure gauge.
– Using a hand-operated vacuum pump, apply vacuum (20
in. Hg) to the regulator. The regulator should hold
vacuum. If the vacuum drops, replace the fuel-pressure
regulator.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
PORT FUEL-INJECTION PRESSURE REGULATOR
DIAGNOSIS
FIGURE 24-1 If the vacuum hose
is removed from the fuelpressure regulator when the
engine is running, the fuel
pressure should increase. If it
does not increase, then the fuel
pump is not capable of supplying
adequate pressure or the fuelpressure regulator is defective. If
gasoline is visible in the vacuum
hose, the regulator is leaking and
should be replaced.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
PRESSURE TRANSDUCER FUEL PRESSURE
TEST
FIGURE 24-2 (a) A fuel-pressure graph after key on, engine off (KOEO). (b)
Pressure drop after 10 minutes on a normal port fuel-injection system.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
DIAGNOSING ELECTRONIC FUEL-INJECTION
PROBLEMS USING VISUAL INSPECTION
• All fuel-injection systems require the proper amount of clean
fuel delivered to the system at the proper pressure and the
correct amount of filtered air.
• The following items should be carefully inspected before
proceeding to more detailed tests.
– Check the air filter and replace as needed.
– Check the air induction system for obstructions.
– Check the conditions of all vacuum hoses. Replace any hose that is
split, soft (mushy), or brittle.
– Check the positive crankcase ventilation (PCV) valve for proper
operation or replacement as needed
– Check all fuel-injection electrical connections for corrosion or
damage.
– Check for gasoline at the vacuum port of the fuel-pressure regulator if
the vehicle is so equipped.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
DIAGNOSING ELECTRONIC FUEL-INJECTION
PROBLEMS USING VISUAL INSPECTION
FIGURE 24-3 A clogged PCV system caused the engine oil fumes to be drawn
into the air cleaner assembly. This is what the technician discovered during a
visual inspection.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
STETHOSCOPE FUELINJECTION TEST
FIGURE 24-4 All fuel injectors should make the same sound with the engine
running at idle speed. A lack of sound could indicate an electrically open injector, a
break in the wiring, or a stuck closed injector. A defective computer could also be
the cause of a lack of clicking (pulsing) of the injectors.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
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STETHOSCOPE FUELINJECTION TEST
FIGURE 24-5 Fuel
should be heard
returning to the fuel tank
at the fuel return line if
the fuel-pump and fuelpressure regulator are
functioning correctly.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
SCAN TOOL VACUUM LEAK DIAGNOSIS
• If a vacuum (air) leak occurs on an engine equipped
with a speed-density-type of fuel injection, the extra
air would cause the following to occur:
– The idle speed increases due to the extra air just as if the
throttle pedal was depressed.
– The MAP sensor reacts to the increased air from the
vacuum leak as an additional load on the engine.
– The computer increases the injector pulse width slightly
longer due to the signal from the MAP sensor.
– The air-fuel mixture remains unchanged.
– The idle air control (IAC) counts will decrease, thereby
attempting to reduce the engine speed to the target idle
speed stored in the computer memory.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
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SCAN TOOL VACUUM LEAK DIAGNOSIS
FIGURE 24-6 Using a
scan tool to check for
IAC counts or
percentage as part of a
diagnostic routine.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
PORT FUEL-INJECTION SYSTEM DIAGNOSIS
• To determine if a port fuel-injection system—including the
fuel pump, injectors, and fuel-pressure regulator—are
operating correctly, take the following steps.
– Attach a fuel-pressure gauge to the Schrader valve on the fuel rail.
– Turn the ignition key on or start the engine to build up the fuel-pump
pressure (to about 35 to 45 PSI).
– Wait 20 minutes and observe the fuel pressure retained in the fuel rail
and note the PSI reading.
•
•
•
•
•
The check valve in the fuel pump
Leaking injectors, lines, or fittings
A defective (leaking) fuel-pressure regulator
Reenergize the electric fuel pump.
Clamp the fuel supply line, and wait 10 minutes (see caution box). If the pressure
drop does not occur, replace the fuel pump. If the pressure drop still occurs,
continue with the next step.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
PORT FUEL-INJECTION SYSTEM DIAGNOSIS
FIGURE 24-7 Checking the fuel pressure using a fuel-pressure gauge
connected to the Schrader valve.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
PORT FUEL-INJECTION SYSTEM DIAGNOSIS
• To determine which unit is defective, perform the
following:
– Reenergize the electric fuel pump.
– Clamp the fuel supply line, and wait 10 minutes (see
caution box). If the pressure drop does not occur, replace
the fuel pump. If the pressure drop still occurs, continue
with the next step.
– Repeat the pressure buildup of the electric pump and
clamp the fuel return line.
– If the pressure drop still occurs, one or more of the
injectors is leaking. Remove the injectors with the fuel rail
and hold over paper. Replace those injectors that drip one
or more drops after 10 minutes with pressurized fuel.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
PORT FUEL-INJECTION SYSTEM DIAGNOSIS
FIGURE 24-8 Shutoff valves must be used on vehicles equipped with plastic
fuel lines to isolate the cause of a pressure drop in the fuel system.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
TESTING FOR AN INJECTOR PULSE
• One of the first checks that should be performed
when diagnosing a no-start condition is whether the
fuel injectors are being pulsed by the computer.
• Checking for proper pulsing of the injector is also
important in diagnosing a weak or dead cylinder.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
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TESTING FOR AN INJECTOR PULSE
FIGURE 24-9 (a) Noid lights are usually purchased as an assortment so that one is available
for any type or size of injector wiring connector. (b) The connector is unplugged from the
injector and a noid light is plugged into the injector connector. The noid light should flash when
the engine is being cranked if the power circuit and the pulsing to ground by the computer are
functioning okay.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
TESTING FOR AN INJECTOR PULSE
• Possible noid light
problems and causes
include the following:
– The light is off and does
not flash.
– The noid light flashes
dimly.
– The noid light is on and
does not flash.
FIGURE 24-10 Use a DMM set to read
DC volts to check the voltage drop of
the positive circuit to the fuel injector. A
reading of 0.5 volt or less is generally
considered to be acceptable.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHECKING FUEL-INJECTOR RESISTANCE
• Each port fuel injector must deliver an equal amount
of fuel or the engine will idle roughly or perform
poorly.
• The electrical balance test involves measuring the
injector coil-winding resistance.
• For best engine operation, all injectors should have
the same electrical resistance.
• To measure the resistance, carefully release the
locking feature of the connector and remove the
connector from the injector.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHECKING FUEL-INJECTOR RESISTANCE
FIGURE 24-11 Connections and
settings necessary to measure fuelinjector resistance. (Courtesy of
Fluke Corporation)
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHECKING FUEL-INJECTOR RESISTANCE
FIGURE 24-12 To measure fuel-injector resistance, a technician constructed a short
wiring harness with a double banana plug that fits into the V and COM terminals of
the meter and an injector connector at the other end. This setup makes checking
resistance of fuel injectors quick and easy.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
MEASURING RESISTANCE OF GROUPED
INJECTORS
• To measure the resistance of these injectors, it is
often easiest to measure each group of three that is
wired in parallel.
• The resistance of three injectors wired in parallel is
one-third of the resistance of each individual
injector.
• For example,
– Injector resistance = 12 ohms (Ω)
– Three injectors in parallel = 4 ohms (Ω)
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
MEASURING RESISTANCE OF GROUPED
INJECTORS
FIGURE 24-13 (a) The meter is connected to read one group of three 12-ohm injectors. The
result should be 4 ohms. This reading is a little low, indicating that at least one injector is
shorted (low resistance). (b) This meter is connected to the other group of three injectors and
indicates that most, if not all three, injectors are shorted. The technician replaced all six
injectors and the engine ran great.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
MEASURING RESISTANCE OF INDIVIDUAL
INJECTORS
• While there are many ways
to check injectors, the first
test is to measure the
resistance of the coil inside
and compare it to factory
specifications.
FIGURE 24-14 If an injector has the specified
resistance, that does not mean that it is okay.
This injector had the specified resistance yet did
not deliver the specified amount of fuel because
it was clogged.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
PRESSURE-DROP BALANCE TEST
• The pressure balance test involves using an
electrical timing device to pulse the fuel injectors on
for a given amount of time, usually 500 ms or 0.5
second, and observing the drop in pressure that
accompanies the pulse.
• If the fuel flow through each injector is equal, the
drop in pressure in the system will be equal.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
PRESSURE-DROP BALANCE TEST
FIGURE 24-15 Connect a fuel-pressure gauge to the fuel rail at the Schrader
valve.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
INJECTOR VOLTAGE DROP TEST
• Another test of injectors
involves pulsing the injector
and measuring the voltage
drop across the windings
as current is flowing.
FIGURE 24-16 An injector tester being
used to check the voltage drop through
the injector while the tester is sending
current through the injectors. This test is
used to check the coil inside the injector.
This same tester can be used to check for
equal pressure drop of each injector by
pulsing the injector on for 500 ms.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
SCOPE TESTING FUEL INJECTORS
• A scope (analog or digital
storage) can be connected
into each injector circuit.
• There are three types of
injector-driven drive circuits
and each type of circuit has
its own characteristic
pattern.
FIGURE 24-17 A digital storage
oscilloscope can be easily connected to an
injector by carefully back probing the
electrical connector.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
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SCOPE TESTING FUEL INJECTORS
• Saturated Switch Type
• Peak-and-Hold Type
• Pulse-Width Modulated
Type
FIGURE 24-18 The injector on-time is
called the pulse width. (Courtesy of Fluke
Corporation)
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
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SCOPE TESTING FUEL INJECTORS
FIGURE 24-19 A typical peak-andhold fuel-injector waveform. Most
fuel injectors that measure less
than 6 ohms will usually display a
similar waveform.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
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IF THREE OF SIX INJECTORS ARE DEFECTIVE,
SHOULD I ALSO REPLACE THE OTHER THREE?
FIGURE 24-20 A set of six reconditioned injectors.
Automotive Fuel and Emissions Control Systems, 2/e
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© 2009 Pearson Higher Education, Inc.
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IDLE AIR SPEED CONTROL DIAGNOSIS
• On an engine equipped with fuel injection (TBI or
port injection), the idle speed is controlled by
increasing or decreasing the amount of air
bypassing the throttle plate.
• Again, an electronic stepper motor or pulse-width
modulated solenoid is used to maintain the correct
idle speed.
• This control is often called the idle air control
(IAC).
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
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IDLE AIR SPEED CONTROL DIAGNOSIS
FIGURE 24-21 An IAC
controls idle speed by
controlling the amount of air
that passes around the
throttle plate. More airflow
results in a higher idle speed.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
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IDLE AIR SPEED CONTROL DIAGNOSIS
FIGURE 24-22 A typical IAC.
Automotive Fuel and Emissions Control Systems, 2/e
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FIGURE 24-23 Some IAC units are
purchased with the housing as shown.
Carbon buildup in these passages can
cause a rough or unstable idling or stalling.
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THERE IS NO SUBSTITUTE FOR A THOROUGH
VISUAL INSPECTION
FIGURE 24-24 (a) Nothing looks unusual when the hood is first opened. (b) When
the cover is removed from the top of the engine, a mouse or some other animal
nest is visible. The animal had already eaten through a couple of injector wires. At
least the cause of the intermittent misfire was discovered.
Automotive Fuel and Emissions Control Systems, 2/e
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© 2009 Pearson Higher Education, Inc.
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FUEL-INJECTION SERVICE
• Fuel-injection system service should include the
following operations:
– Check fuel-pump operating pressure and volume.
– Test the fuel-pressure regulator for operation and
leakage.
– Flush the entire fuel rail and upper fuel-injector
screens including the fuel-pressure regulator.
– Clean the fuel injectors.
– Decarbon the engine assembly.
– Clean the throttle plate and idle air control passages.
– Relearn the onboard computer.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FUEL-INJECTION SERVICE
FIGURE 24-25 Checking
fuel-pump volume using a
hose from the outlet of the
fuel-pressure regulator
into a calibrated container.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
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FUEL-INJECTION SERVICE
FIGURE 24-26 Testing
fuel-pump volume
using a fuel-pressure
gauge with a bleed
hose inserted into a
suitable container. The
engine is running
during this test.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
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FUEL-INJECTION SERVICE
FIGURE 24-27 A typical two-line cleaning machine hookup, showing an extension
hose that can be used to squirt a cleaning solution into the throttle body while the
engine is running on the cleaning solution and gasoline mixture.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
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FUEL-INJECTION SERVICE
FIGURE 24-28 To thoroughly clean a throttle body, it is sometimes best to
remove it from the vehicle.
Automotive Fuel and Emissions Control Systems, 2/e
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© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FUEL-SYSTEM SCAN TOOL DIAGNOSTICS
• Diagnosing a faulty fuel system can be a difficult
task.
• However, it can be made easier by utilizing the
information available via the serial data stream.
• By observing the long-term fuel trim and the shortterm fuel trim, we can determine how the fuel
system is performing.
• Short-term fuel trim and long-term fuel trim can help
us to zero in on specific areas of trouble.
• Readings should be taken at idle and at 3000 RPM.
Use the following chart as a guide.
Automotive Fuel and Emissions Control Systems, 2/e
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FUEL-PUMP RELAY CIRCUIT DIAGNOSIS
Automotive Fuel and Emissions Control Systems, 2/e
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© 2009 Pearson Higher Education, Inc.
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FUEL-PUMP RELAY CIRCUIT DIAGNOSIS
Automotive Fuel and Emissions Control Systems, 2/e
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© 2009 Pearson Higher Education, Inc.
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FUEL-PUMP RELAY CIRCUIT DIAGNOSIS
Automotive Fuel and Emissions Control Systems, 2/e
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FUEL-PUMP RELAY CIRCUIT DIAGNOSIS
Automotive Fuel and Emissions Control Systems, 2/e
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FUEL-PUMP RELAY CIRCUIT DIAGNOSIS
Automotive Fuel and Emissions Control Systems, 2/e
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FUEL-PUMP RELAY CIRCUIT DIAGNOSIS
Automotive Fuel and Emissions Control Systems, 2/e
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FUEL-PUMP RELAY CIRCUIT DIAGNOSIS
Automotive Fuel and Emissions Control Systems, 2/e
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FUEL-PUMP RELAY CIRCUIT DIAGNOSIS
Automotive Fuel and Emissions Control Systems, 2/e
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FUEL-PUMP RELAY CIRCUIT DIAGNOSIS
Automotive Fuel and Emissions Control Systems, 2/e
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FUEL INJECTOR CLEANING
Automotive Fuel and Emissions Control Systems, 2/e
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FUEL INJECTOR CLEANING
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
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FUEL INJECTOR CLEANING
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
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Pearson Prentice Hall - Upper Saddle River, NJ 07458
FUEL INJECTOR CLEANING
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
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FUEL INJECTOR CLEANING
Automotive Fuel and Emissions Control Systems, 2/e
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FUEL INJECTOR CLEANING
Automotive Fuel and Emissions Control Systems, 2/e
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SUMMARY
1. A typical throttle-body fuel injector uses a
computer-controlled injector solenoid to spray fuel
into the throttle-body unit above the throttle plates.
2. A typical port fuel-injection system uses an
individual fuel injector for each cylinder and squirts
fuel directly into the intake manifold about 3 inches
(80 millimeters) from the intake valve.
3. A typical fuel-injection system fuel pressure should
not drop more than 20 PSI in 20 minutes.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
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SUMMARY
4. A noid light can be used to check for the presence
of an injector pulse.
5. Injectors can be tested for resistance and should
be within 0.3 to 0.4 ohms of each other.
6. Different designs of injectors have a different
scope waveform depending on how the computer
pulses the injector on and off.
7. An idle air control unit controls idle speed and can
be tested for proper operation using a scan tool or
scope.
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
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REVIEW QUESTIONS
1. List the ways fuel injectors can be tested.
2. List the steps necessary to test a fuel-pressure
regulator.
3. Describe why it may be necessary to clean the
throttle plate of a port fuel-injected engine.
Automotive Fuel and Emissions Control Systems, 2/e
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CHAPTER QUIZ
1. Most port fuel-injected engines should have an
operating fuel pressure of _____.
a)
b)
c)
d)
3 to 5 PSI (21 to 35 kPa)
9 to 13 PSI (62 to 90 kPa)
35 to 45 PSI (240 to 310 kPa)
55 to 65 PSI (380 to 450 kPa)
Automotive Fuel and Emissions Control Systems, 2/e
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© 2009 Pearson Higher Education, Inc.
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CHAPTER QUIZ
1. Most port fuel-injected engines should have an
operating fuel pressure of _____.
a)
b)
c)
d)
3 to 5 PSI (21 to 35 kPa)
9 to 13 PSI (62 to 90 kPa)
35 to 45 PSI (240 to 310 kPa)
55 to 65 PSI (380 to 450 kPa)
Automotive Fuel and Emissions Control Systems, 2/e
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CHAPTER QUIZ
2. Fuel injectors can be tested using _____.
a)
b)
c)
d)
An ohmmeter
A stethoscope
A scope
All of the above
Automotive Fuel and Emissions Control Systems, 2/e
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© 2009 Pearson Higher Education, Inc.
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CHAPTER QUIZ
2. Fuel injectors can be tested using _____.
a)
b)
c)
d)
An ohmmeter
A stethoscope
A scope
All of the above
Automotive Fuel and Emissions Control Systems, 2/e
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CHAPTER QUIZ
3. Throttle-body fuel-injection systems use what type
of injector driver?
a)
b)
c)
d)
Peak and hold
Saturated switch
Pulse-width modulated
Pulsed
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
3. Throttle-body fuel-injection systems use what type
of injector driver?
a)
b)
c)
d)
Peak and hold
Saturated switch
Pulse-width modulated
Pulsed
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
4. Port fuel-injection systems generally use what type
of injector driver?
a)
b)
c)
d)
Peak and hold
Saturated switch
Pulse-width modulated
Pulsed
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
4. Port fuel-injection systems generally use what type
of injector driver?
a)
b)
c)
d)
Peak and hold
Saturated switch
Pulse-width modulated
Pulsed
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
5. The vacuum hose from the fuel-pressure regulator
was removed from the regulator and gasoline
dripped out of the hose. Technician A says that is
normal and that everything is okay. Technician B
says that one or more of the injectors may be
defective, causing the fuel to get into the hose.
Which technician is correct?
a)
b)
c)
d)
Technician A only
Technician B only
Both Technicians A and B
Neither Technician A nor B
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
5. The vacuum hose from the fuel-pressure regulator
was removed from the regulator and gasoline
dripped out of the hose. Technician A says that is
normal and that everything is okay. Technician B
says that one or more of the injectors may be
defective, causing the fuel to get into the hose.
Which technician is correct?
a)
b)
c)
d)
Technician A only
Technician B only
Both Technicians A and B
Neither Technician A nor B
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
6. The fuel pressure drops rapidly when the engine is
turned off. Technician A says that one or more
injectors could be leaking. Technician B says that a
defective check valve in the fuel pump could be
the cause. Which technician is correct?
a)
b)
c)
d)
Technician A only
Technician B only
Both Technicians A and B
Neither Technician A nor B
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
6. The fuel pressure drops rapidly when the engine is
turned off. Technician A says that one or more
injectors could be leaking. Technician B says that a
defective check valve in the fuel pump could be
the cause. Which technician is correct?
a)
b)
c)
d)
Technician A only
Technician B only
Both Technicians A and B
Neither Technician A nor B
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
7. In a typical port fuel-injection system, the fuel
pressure is regulated _____.
a) By a regulator located on the fuel return side of the fuel
rail
b) By a regulator located on the supply side of the fuel rail
c) By the computer by pulsing the regulator on and off
d) Either b or c
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
7. In a typical port fuel-injection system, the fuel
pressure is regulated _____.
a) By a regulator located on the fuel return side of the fuel
rail
b) By a regulator located on the supply side of the fuel rail
c) By the computer by pulsing the regulator on and off
d) Either b or c
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
8. What component pulses the fuel injector on most
vehicles?
a)
b)
c)
d)
Electronic control unit (computer)
Ignition module
Crankshaft sensor
Both b and c
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
8. What component pulses the fuel injector on most
vehicles?
a)
b)
c)
d)
Electronic control unit (computer)
Ignition module
Crankshaft sensor
Both b and c
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
9. Fuel injection service is being discussed.
Technician A says the throttle plate(s) should be
cleaned. Technician B says that the fuel rail should
be cleaned. Which is correct?
a)
b)
c)
d)
Technician A only
Technician B only
Both Technicians A and B
Neither Technicians A nor B
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
9. Fuel injection service is being discussed.
Technician A says the throttle plate(s) should be
cleaned. Technician B says that the fuel rail should
be cleaned. Which is correct?
a)
b)
c)
d)
Technician A only
Technician B only
Both Technicians A and B
Neither Technicians A nor B
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
10. If the throttle plate needs to be cleaned, what
symptoms will be present regarding the operation
of the engine?
a)
b)
c)
d)
Stalls
Rough idle
Hesitation on acceleration
All of the above
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
10. If the throttle plate needs to be cleaned, what
symptoms will be present regarding the operation
of the engine?
a)
b)
c)
d)
Stalls
Rough idle
Hesitation on acceleration
All of the above
Automotive Fuel and Emissions Control Systems, 2/e
By James D. Halderman and Jim Linder
© 2009 Pearson Higher Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458