PONTIAC FIERO 1988 Service Repair Manual

6E-18 DRIVEABILITY AND EMISSIONS - FUEL INJECRON
CCP (Carbon Canister Purge)
This displays "ON" when the canister purge
solenoid is commanding purge. Some display duty
cycle from
0-1008.
2nd Gear
This displays the state of the 2nd gear switch.
Yes=2nd gear applied. It remains applied in 3rd and
4th gears.
3rd Gear
This displays the state of the 3rd gear switch.
Yes= 3rd gear applied. It remains applied in 4th gear.
4th Gear
This displays the state of the 4th gear switch.
Yes
= 4th gear applied.
Fan Request
State of the AJC fan control switch is displayed. It
should read "yes" when fan is requested. Some
engines may display the state of the 2nd fan, if used.
Power Steering Pressure Switch
This reading displays the state of switch, and may
vary with the tool used, and the type of switch
installed on the vehicle. The important thing is that
the reading changes state (switches) when the
steering is moved against the stops.
Electronic Control Module (ECM)
This section describes the ECM and the
information sensors in the system. Figure
4 shows
the operating conditions which the ECM may sense
and the systems that the ECM may control. (See
specific engines to determine which are applicable
to
that engine.)
Fuel Control System
The ECM controls the aidfuel delivery to the
combustion chamber by controlling the fuel flow
through the
injector(s).
Electric Fuel Pump (In-tank)
The in-tank fuel pump is controlled by the ECM.
When ignition is turned "ON", the pump will run for 2
seconds, then stop unless the ECM is receiving
ignition pulses, as when cranking or running.
Evaporative Emission ControI
This system has a canister which stores fuel vapor
from the fuel tank. The fuel vapor is removed from the
canister and consumed in the normal combustion
process when the engine is running. This system is
used on all engines and may or may not be controlled
by the ECM.
ilectronic Spark Timing (EST)
This system is controlled by the ECM, which
controls spark advance (timing), and is used on all
engines.
SECTION B - DRIVEABILIW SYMPTOMS Electronic Spark
Control (ESC)
Always start with Section "A" "Diagnostic Circuit
Check" before proceeding to the driveability
symptoms or an emissions test failure. Section "A"
checks the ECM, which may cause the driveability
problem. A definition of each symptom is included.
This will then lead to the most probable causes of the
driveability problem.
SECTION C - COMPONENT SYSTEMS
There are many component systems that are used
to control fuel and emissions. Section
"C" introduces
each component system or control with a general
description, diagnosis, and on-vehicle service.
Each of the Section "C" diagnosis sections contain
information on how the "ScanJ' tool can be used for
diagnosing a particular component when a trouble
code has not been set. (example: Section
"Cl" under
diagnosis will explain how the "Scan" tool can be used
for diagnosis as well as what the normal readings
would be for the
ECM sensors.) This
system uses a knock sensor in connection
with the ECM to control spark timing, to allow the
engine to have maximum spark advance without
spark knock. This improves driveability and fuel
economy, but will retard spark
if detonation (spark
knock) is detected.
Air Injection Reaction (A.I.R.)
The system provides additional oxygen to the
exhaust gases to continue the combustion process.
The system also supplies additional air to the catalytic
converter under certain conditions. The A.I.R. system
is not on all engines.
Early Fuel Evaporation (EFE)
The EFE system heats the engine induction
system electrically or with exhaust gas during cold

DRIVEABILITY AND EMISSIONS - FUEL INJEC"F0N 6E-11
@ A/% "On" or "Off" r Air Management
r Engine Coolant Temwrature r Canister Purge
@ Engine crank signal r Exhaust Gas Recirculation (EGR)
@ Exhaust Oxygen(02) Sensor @ Electronic Spark Timing (EST)
r Distributor Reference @ Fuel Control
@ Crankshaft Position @ Idle Air Control (lAC)
@ Engine Speed (RPM) Transmission Converter Clutch (TCC)
Manifold Absolute Pressure (MAP)
@ Park Neutral Switch (PB) Position @ Electric Fuel Pump
r System Voltage Air Conditioning
r Throttle Position (TPS) @ Engine Cooling Fan
r Transmission Gear Position
r Vehicle Speed (VSS) @ "Service Engine Soon" Light
@ Fuel Pump Voltage @ Diagnostic Terminal (ALDL)
r Power Steering Pressure @ Data Output (ALDL)
Mass Air Flow (MAF) @ Electronic Spark Control (ESC)
@ Manifold Air Temperature (MAT) @ Early Fuel Evaporation (EFE)
r EGR Vacuum @ Idle Speed (ISC, ILC,)
@ Engine Knock (ESC)
r Differential Pressure (VAC) 6-1-87
*7S
3429- 6E
Figure
4 - ECM Operating Conditions Sensed and Systems Controlled
driveaway. This system is not used on all engines and Electric Cooling Fan Control
may or may not be controlled by the ECM.
Under certain conditions, the
ECM may control
Exhaust Gas Recirculation (ECR) the electric cooling fan to cool the engine and A/C
condenser. At cruising speed, the ECM may turn the
The
EGR system uses a valve to feed a small fan
off for better fuel economy. This control is on
amount of exhaust gas back into the intake manifold transverse
engine front wheel drive vehicles.
to control formation of
NO,.
Positive Crankcase Ventilation (PCV) or
Transmission Converter
Clutch (TCC) Crankcase Ventilation (CV)
The TCC is ECM controlled and is used on all
engines with an automatic transmission. This system
reduces slippage losses in the torque converter by
coupling the engine flywheel to the output shaft of the
transmission.
Shift Light Control
The ECM controls the shift light on some manual
transmission vehicles to indicate the best shift point
for maximum fuel economy. This control is not on all
applications.
NC Clutch Control
The ECM may control the AJC clutch on the
compressor to improve idle quality. This control is not
on all engines. The
PCV or CV system passes crankcase vapors
into the intake manifold. This system is not controlled
by the
ECM and is used on all engines.
Thermostatic Air Cleaner (THERMAC)
The THERMAC system regulates heated air
through the air cleaner to provide uniform inlet air
temperature, which gives good driveability under
various climatic conditions. This system is not
controlled by the
ECM.
ABBREVIATIONS AND GLOSSARY OF TERMS
Abbreviations used in this section are listed below
in alphabetical order with an explanation of the
abbreviation. There are some variations in the use of
periods and in capitalization (as mph,
m.p.h., Mph,

6E-12 DRIVEABILITY AND EMISSIONS - FUEL INJECUION
and MPH) for abbreviations used in this Section, but
all types are acceptable.
NA/F - AI WFUEL (NF RATIO)
A.I.R.
- AIR INJECTOR REACTION SYSTEM - Air
flow from pump is directed into engine exhaust
manifold
and/or converter to reduce exhaust
emissions.
ALDL - ASSEMBLY LINE DIAGNOSTIC LINK - Used
at assembly to evaluate Computer Command Control,
and for service to flash the "Service Engine Soon"
light
if there are trouble codes. It also is used by
"Scan" tools to obtain ECM serial data.
BARO - BAROMETRIC ABSOLUTE PRESSURE
SENSOR
- Reads atmospheric pressure.
B + - Battery Positive Terminal (12 Volts) or
system voltage with the engine running
(approximately 13.8
v.)
CALPAK - A device used with fuel injection to
allow fuel delivery in the event of a PROM or ECM
malfunction.
CALIBRATOR - (PROM) - An electronic component
that can be
specifically programmed to meet engine
operating requirements for a
specific vehicle model.
It plugs into the Engine Control Module
(ECM).
CCC - COMPUTER COMMAND CONTROL - has an
electronic control module to control airlfuel and
emission systems.
CLCC - CLOSED LOOP CARBURETOR CONTROL -
Used to describe oxygen sensor to ECM to MIC
solenoid circuit operation.
C3I - Computer Controlled Coil Ignition. Produces
the ignition spark without the aid of an ignition
distributor.
CCP - CONTROLLED CANISTER PURGE - ECM
controlled solenoid valve that permits manifold
vacuum to purge the evaporative emissions from the
charcoal canister.
CID - CUBIC INCH DISPLACEMENT - Used to
describe engine size.
UL OR ULOOP - "CLOSED LOOP" - Describes ECM
fuel control when using oxygen sensor information.
COOLANT TEMPERATURE SENSOR - Device that
senses the engine coolant temperature, and passes
that information to the engine control module.
CONV. - CATALYTIC CONVERTER, THREE-WAY -
EXHAUST CONVERTER. Containing platinum and
palladium to speed up conversion of
HC and CO, and
rhodium to accelerate conversion of NO,.
CO - CARBON MONOXIDE - One of the pollutants
found in engine exhaust.
6V - CRANKCASE VENTlhaflON - Prevents fumes
in crankcase from passing into the atmosphere, by
drawing them into the intake manifold and burning
them in the the combustion process.
DIAGNOSTIC CODE - Pair of numbers obtained
from flashing "Service Engine Soon" light or
displaying on a "Scan" tool. This code can be used to
determine the system malfunction.
DIAGNOSTIC TERM. - Lead of ALDL Connector
which is grounded to get a Trouble Code.
It is
grounded with the engine running to enter the "Field
Service Mode".
DIS - Direct Ignition System. Produces the
ignition spark without the aid of an ignition
distributor.
DVM (10 Meg.) - Digital Voltmeter with 10 Million
ohms resistance
- used for measurement in electronic
systems.
DWELL - The amount of time (recorded on a dwell
meter in degrees of crankshaft rotation) that current
passes through a closed switch; for example, ignition
contact points or internal switch in an electronic
control module.
EAC - ELECTRIC AIR CONTROL - Used on A.I.R.
system to direct air flow to air switching valve or to
atmosphere.
EAS - ELECTRIC AIR SWITCHING - used to direct air
flow to catalytic converter or exhaust ports of the
engine.
ECM - ENGINE CONTROL MODULE (ELECTRONIC) -
A metal case (located in passenger compartment)
containing electronic circuitry which electrically
controls and monitors airlfuel and emission systems
on computer command control, and turns
"ON" the
"Service Engine Soon" light when a malfunction
occurs in the system.
EFI - ELECTRONIC FUEL INJECTION - Computer
Command Control using throttle body fuel injection.
EGR - EXHAUST GAP REClRCUbATlON - Method of
reducing NO, emission levels by causing exhaust gas
to be added to airlfuel mixture in combustion
chamber, thus cooling combustion.
EECS - EVAPORATIVE EMISSIONS CONTROL
SYSTEM
- Used to prevent gasoline vapors in the fuel
tank from entering the atmosphere.
EFE - EARLY FUEL EVAPORATION - Method of
warming the intake manifold during cold engine
operation. Provides efficient airlfuel mixing.
ENERGIZEIDE-ENERGIZE - When current is passed
through a coil (energized) such as the canister purge
solenoid, the plunger is pulled into the solenoid.

DRIVEABILIW AND EMISSIONS - FUEL INJECTION 6E-13
When the voltage to the solenoid is turned off, (de-
energized), a spring raises the plunger.
ESC - ELECTRONIC SPARK CONTROL - Used to
sense detonation and retard spark advance when
detonation occurs.
EST - ELECTRONIC SPARK TIMING - ECM
controlled timing of ignition spark.
EVRV - ELECTRONIC VACUUM REGULAWR
VALVE - Controls EGR vacuum.
FED - FEDEWL - VehicleIEngine available in all
states except California.
GROUND - The negative (-) side of the battery.
Also could be a wire (conductor) shorted to ground.
HC - HYDROCARBONS - One of the pollutants
found in engine exhaust.
HIGH IMPEDANCE VOLTMETER - Mas high
opposition to the flow of electrical current.
Good for
reading circuits with low current flow, such as found
in electronic systems because it allows tests to be
made without affecting the circuit.
HE1 - HIGH ENERGY IGNITION - A distributor that
uses an electronic module and pick-up coil in place of
contact points.
Hg - MERCURY - A calibration material used as a
standard for vacuum measurement.
IAC - IDLE AIR CONTROL - A valve installed in the
throttle body of fuel injected systems and controlled by
the ECM to regulate idle speed.
IDEAL MIXWRE - The airlfuel ratio which provides
the best performance, while maintaining maximum
conversion of exhaust emissions. Typically it is
14.7:1.
ID1 - INTEGRATED DIRECT IGNITION - Produces the
ignition spark without the aid of an ignition
distributor or spark plug wires.
IDLE AIR BLEED VALVE - Controls the amount of
air let into the idle fuel mixture prior to the mixture
entering the carburetor idle system, when the
MIC
solenoid is energized.
ILC - IDLE LOAD COMPENSATOR - Device used to
control throttle angle during long deceleration, such
as coasting down a long grade; it extends at wide open
throttle position or to prevent engine stalls at idle.
INPUTS - Information from sources (such as
coolant temperature sensors, exhaust oxygen sensor,
etc.) to the ECM that indicate how the systems are
performing.
INTERMITTENT - Occurs now and then; not
continuously. In electrical circuits, refers to
occasional open, short, or ground.
I.P. - INSTRUMENT PANEL
ISC - IDLE SPEED CONTROL - Regulates throttle
valve position to control idle speed. Idle speed is
controlled by the ECM and is not adjustable.
KMIHR - KILOMEnR PER HOUR - A metric unit
measuring speed needed to travel distance of one
kilometer (1000 meters) in one hour.
L - LITER - A metric unit of capacity.
L4 - FOUR CYLINDER IN-LINE ENGINE
MAF - MASS AIR FLOW - Sensor which measures
the amount of air entering the engine.
MALFUNCTION - A problem that causes the
system to operate incorrectly. Typical malfunctions
are wiring harness opens or shorts, failed sensors or
circuit components.
MANIFOLD VACUUM SENSOR - Indicates vacuum
in the intake manifold by measuring the pressure in
intake manifold in relation to barometric pressure. It
is also called a differential pressure sensor because
it
measures the difference between the two pressures. It
puts out a voltage which is highest when the vacuum
is highest. The maximum voltage is between 4 and 5
volts.
MAP - MANIFOLD ABSOLUTE PRESSURE SENSOR -
Reads pressure changes in intake manifold with
reference to zero pressure. It puts out a voltage which
is highest when the pressure is highest. The
maximum voltage is between
4 and 5 volts.
MAT - Manifold Air Temperature Sensor.
Measures temperature of air in the intake manifold.
MIC - MIXTURE CONTROL
MEM-CAL
- MEMORY CALIBRATOR - Contains
specific calibrations to meet the requirements of a
specific engine.
MFI - MULTlPORT FUEL INJECnON - Individual
injectors for each cylinder are mounted in the intake
manifold. The injectors are fired in groups rather than
individually.
MIXTURE CONTROL (MIC) SOLENOID - Device,
installed in carburetor, to regulate the airlfuel ratio.
MODE - A particular state of operation.
MPH - MILES PER HOUR - A unit measuring speed
needed to travel distance of one mile (5280 feet) in one
hour.
N.C. - NORMALLY CLOSED - State of relay contacts
or solenoid plunger when no voltage is applied.
N-rn - NEWTON METER (Torque) - A metric unit
describing force.

6E-14 DRIVEABILITY AND EMISSIONS - FUEL INJECTION
N.O. - NORMALLY OPEN - State of relay contacts
or solenoid plunger when no voltage
is applied.
NOx - NITROGEN, OXIDES OF - One of the
pollutants found in engine exhaust.
O2 - OXYGEN (Sensor) - Monitors the oxygen
content of the exhaust system and generates a voltage
signal to the ECM.
OIL or OILOOP - OPEN LOOP - Describes ECM fuel
control without use of oxygen sensor information.
OUTPUT - Result of a function typically controlled
by the ECM.
OXYGEN SENSOR. EXHAUST - Device that detects
the amount of oxygen
(02) in the exhaust stream.
P.A.1.R - PULSE AIR INJECTION REACTOR system -
pulsed air directed into engine to reduce exhaust
emissions.
PCV - POSITIVE CRANKCASE VENTILATION -
Prevent fumes in crankcase from passing into
atmosphere.
PFI - PORT FUEL INJECTION
PIN
- PARWNEUTWL
PORT - EXHAUST OR INTAKE PORT
PROM
- PROGRAMABLE READ ONLY MEMORY-
an electronic term used to describe the engine
calibration unit
.
RPM - REVOLUTIONS PER MINUTE - A measure of
rotational speed.
RVB - REAR VACUUM BMKE - is used to control
choke operation during cold engine conditions.
SELF-DIAGNOSTIC CODE - The ECM can detect
malfunctions in the system.
If a malfunction occurs,
the ECM turns on the "Service Engine Soon" light.
A
diagnostic code can be obtained from the ECM
through the "Service Engine Soon" light, or by use of a
"Scan" tool. This code will indicate the area of the
malfunction.
SES - SERVICE ENGINE SOON LIGHT - Lights when
a malfunction occurs in Computer Command Control
system.
TACH - TACHOMETER
TBI
- THROTTLE BODY INJECTION (Unit) - is
controlled by the ECM to supply precise airlfuel
mixture into the intake manifold.
TCC - TWNSMISSION I TRANSAXLE CONVERTER
CLUTCH
- ECM controlled solenoid in transmission
which positively couples the transmission to the
engine.
THERMAC - THERMOSTATIC AIR CLEANER -
provides preheated air to intake manifold to provide
better driveability when engine
is cold.
TPS - THROnLE POSITION SENSOR - Device that
tells the ECM the throttle position.
TVS - THERMAL VACUUM SWITCH - Used to
control vacuum in relationship to engine temperature.
V - VOLT
V-6 - SIX CYLINDER ENGINE - Two banks of
cylinders, arranged in a
"V".
V-8 - EIGHT CYLINDER ENGINE - Two banks of
cylinders, arranged in a
"V".
VACUUM - Negative pressure; less than
atmospheric pressure.
VACUUM, MANIFOLD - Vacuum source in
manifold below throttle plate.
VACUUM, PORTED - A vacuum source above I (atmospheric side ) of closed throttle plate. , I
WAC SENSOR - Abbreviation for differential
pressure sensor which is a
vacuum sensor.
VIN - VEHICLE IDENTIFIUTION NUMBER. 1
VSS - VEHICLE SPEED SENSOR - Sensor which
sends vehicle speed information to the ECM.
WASTECATE - A means of controlling the amount
of boost available for a Turbo charged engine.
WOT- WIDE OPEN THROPTLE. I
WIRING HARNESS SERVICE I
The ECM wire harness electrically connects the
ECM to the various solenoids, switches, and sensors in
vehicle engine compartment. The ECM is located
inside the vehicle passenger compartment.
Most connectors in the engine compartment are
protected against moisture and dirt which could create
oxidation and deposits on the terminals. This
protection is important because of the very low voltage
and current levels found in the electronic system. The
connectors have a lock which secures the male and
female terminals together. A secondary lock holds the
seal and terminal into the connector.
GENERAL
Molded-on connectors (like Metri-Pack) require
complete replacement of the connector. This means
splicing a new connector assembly into the harness.

DRIVEABILITY AND EMISSIONS - FUEL INJECIION 6E-15
1. REMOVE OUTER JACKET. 2. UNWRAP ALUMINYM/MYbAR TAPE. DO NOT
REMOVE MYLAR. 4. LOCATE DAMAGED WIRE. 2. REMOVE INSULATION ASBEOUIRED.
3. UNTWIST CONDUCTORS. STRIP INSULATION AS 3. SPLICE TWO WIRES TOGETHER USING SPLICE
NECESSARY. CLIPS AND ROSIN CORE SOLDER.
4. COVER SPLICE WlTH TAPE TO INSULATE
FROM OTHER WIRES.
5. RETWIST AS BEFORE AND TAPE WITH ELECTRICAL TAPE AND HOLD IN PLACE.
6. TAPE OVER WHOLE BUNDLE TO SECURE AS BEFORE.
Figure 5 - Wire Harness Repair
WIRE HARNESS
Wire harnesses should be replaced with proper
part number harnesses. When signal wires are spliced
into a harness, use wire with high temperature
insulation only. See Figure
6 for instructions.
With the low current and voltage levels found in
the system, it
is important that the best possible bond
at all wire splices be
made by soldering the splices as
shown.
Use care when probing the connector or replacing
terminals in them. It is possible to short between
opposite terminals. If this happens to the wrong
terminal pair, it is possible
to damage certain
components. Always use jumper wires between
connectors for circuit checking.
NEVER probe
through the Weather-Pack seals or insulation. Even connectors
look similar but are serviced differently.
Replacement connectors and terminals are listed in
Group 8.965 of the Standard Parts Catalog.
Weather-Pack .
Some connectors used with an ECM are called
Weather-Pack. Figure
6 shows a Weather-Pack
terminal and the tool
(5-28942, BT-8234-A or
equivalent) required to service it. This tool is used to
remove the pin and sleeve terminals. If removal is
attempted with an ordinary pick, there is a good
chance that the terminal will be bent or deformed and,
unlike standard blade type terminals, these terminals
cannot be straightened once they are bent.
microscopic damage or holes may result in eventual
Make certain that the connectors are properly
water intrusion,
corr~sion an& or component or circuit
seated and all of the sealing rings in place when
failure. connecting leads. The hinge type flap provides a
When diagnosing, open circuits are often
difficult backup, or secondary locking feature for the
to locate by sight because oxidation or terminal
connector.
misalignment are hidden by the connectors. Merely
wiggling a connector on a sensor or in the wiring They
are used to improve the connector reliability
harness may correct the open circuit condition. This by
retaining the terminals
if the small terminal lock
should always be considered when an open circuit or tangs are not
positioned properly.
failed sensor is indicated. Intermittent problems may
Weather-pack connections cannot be replaced
also be caused by oxidized or loose connections.
with standard connections. Instructions are provided
Before making a connector repair, be certain of the
with Weather-pack connector and terminal packages.
type
of connector. Weather-Pack and Compact Three

6E-16 DRIVEABILIW AND EMISSIONS - FUEL INJECTION
BODY BODY
1. OPEN SECONDARY LBCK YlNGE ON CONNECTOR
2. REMOVE TERMINAL USING TOOL
PUSH TO
RELEASE
A. SLIP NEW SEAL ONTO WIRE.
EAL
6. PUSH TERMINAL AND CONNECTOR AND
ENGAGE LOCKING TANGS.
Figure
6 - Weather-Pack Terminal Repair
Compact Three
The compact three connector, which looks similar
to a Weather-pack connector, is not sealed and is used
where resistance to the environment is not required.
This type of connector most likely is used at the air
control solenoid, Use the standard method when
repairing a terminal. Do not use the Weather-pack
terminal tool J-28742,
Melri-Pack Series 150 - Terminal Removal
Some connectors used to connect various sensors
to the ECM harness use terminals called "Metri-Pack"
(Figure 7). These may be used at the Coolant Sensors
as well as at ignition modules.
They are also called "Pull-To-Seat" terminals
because, to install a terminal on a wire the wire is first
inserted through the seal (5) and, connector
(4). The
terminal is then crimped on the wire, and the terminal
pulled back into the connector to seat it in place.
To remove a terminal:
1. Slide the seal back on the wire,
2. Insert tool (3) BT-8518 or
J 35689, or
equivalent, as shown in insert "A" and "B"
to release the terminal locking tang (2).
3. Push the wire and terminal out through
the connector.
If you are reusing the terminal, reshape the
locking tang (2).
Micro-Pack
Some connectors used on harness to connect to the
ECM are called Micro-Pack (Figure 8). Terminal
replacement requires the use of special tool
5-33095,
BT-8234-A or equivalent.
1. METRI-PACK SERIES 3. TOOL 135689 OR BT-8446
150 FEMALE TERMINAL 4. CONNECTOR BODY
2. LOCKING TANG 5. SEAL
Figure
7 - Metri-Pack Series 150 Terrninal Removal

DRIVEABILITY AND EMISSIONS - FUEL INJECTION 6E-17
ON THE CABLE TO REMOVE TERMINAL. 4. VISUALLY CHECK TERMINAL AND
REPLACE IF TERMINAL CAVITY OR TANG
- -- IS DAMAGED. 5. INSTALL TERMINAL INTO CONNECTOR . 1. GRASP CABLE AND PUSH 1 ERMINAL CAVITY UNTIL LOCKING TANG HAS
TO THE MOST FORWARD POSITION.
SNAPPED INTO POSITION.
2. INSERT TOOL 533695 STRAIGHT INTO
THE FRONT OF THE CONNECTOR CAVITY.
DO NOT USE CONVENTIONAL
PICK TO REMOVE
TERMINAL.
0321 84. 5% 1418-6E
Figure 8 - Micro-Pack Terminal Replacement
TOOLS NEEDED TO SERVICE THE SYSTEM
The system requires an ALDL read-out ("Scan")
tool, tachometer, test light, ohmmeter, digital
voltmeter with 10 megohms impedance
(5-2912514,
J-34029A or equivalent), vacuum gage and jumper
wires for diagnosis. A test light or voltmeter must be
used when specified in the procedures. They must
NOT be interchanged. See Figures 9 through 13 for
Special Tools needed to diagnosis or repair a system.
For more complete information on the operation of
these tools, see the manufacturer's instructions.

6E-18 DRIVEABILITY AND EMISSIONS - FUEL INJECTION
VOLTMETER - Voltage Position Measures amount of
voltage. When connected in parallel to an existing
circuit.
A digital voltmeter with 90 meg ohm input
impedence
is used because this type of meter will
not load down the circuit and result in faulty
AMMETER -When used as ammeter, this meter also
accurately measures extremely low current flow.
Refer to
meter instructions for more information.
Selector
must be set properly for both function
and range.
DC is used
for most automotive
measu rements.
OHMMETER - Measures resistance of circuit directly
in ohms. Refer to meter for more information.
@ Ob Display in all ranges indicates open circuit.
Zero display in all ranges indicates
a short
@ Intermittent connection in circuit may be
indicated by digital reading that will not
stabilize on circuit.
Range Switch.
HIGH IMPEDANCE MULTIMETER ZOOn - Reads ohms directly
2KfZOKfZ00KR - Reads ohms in thousands
ZM and ZOMn - Reads ohms in millions
Used to check wiring for complete circuit and short to
ground or voltage.
"FACHOMETER
Use inductive trigger signal pickup type to check RPM.

DRIVEABILITY AND EMISSIONS - FUEL INJECTION 6E-19
OXYGEN SENSOR WRENCH
Used to remove or install the oxygen sensor.
IDLE AIR CONTROL WRENCH
Used to remove or install IAC valve on throttle body.
PORT FUEL INJECTION DIAGNOSTIC KIT
Used to diagnose poPt fuel injection systems.
The kit includes:
@ Fuel Pressure Gage -to check fuel pump pressure
and compare injector pressure drop for equal fuel
distribution. lnjector Test Light -to check electrical circuit to an
injeclor.
@ Injector Tester - to energize each fuel injector for a
precise amount of time to perform injector balance
test in
CHART C-2A by checking each injector's
pressure drop using pressure gage.
FUEL PRESSURE GAGE
Used to check and monitor fuel line pressure of port
fuel system.
Part of Diagnostic Kit 134730-A
INJECTOR TEST LIGHT
Used to check electrical circuit to a port fuel injector
Pae of Diagnostic Kit 134730-A
INJECTOR TEST LIGHT
Used to check eledrical circuit to a TBI fuel injector
(except
TBI 700)
INJECTOR TEST LIGHT
Used to check electrical circuit to a TBI 700 fuel
injector and a port fuel injector.
5-2-86
75 3396-6E