Vacuum JEEP WRANGLER 1994 User Guide
[x] Cancel search | Manufacturer: JEEP, Model Year: 1994, Model line: WRANGLER, Model: JEEP WRANGLER 1994Pages: 1770, PDF Size: 75.27 MB
Page 109 of 1770

SPEED CONTROLÐPCM OUTPUT
Speed control operation is regulated by the power-
train control module (PCM). The PCM controls the
vacuum to the throttle actuator through the speed
control vacuum and vent solenoids. Refer to Group
8H for speed control information.
TACHOMETERÐPCM OUTPUT
The powertrain control module (PCM) supplies en-
gine rpm values to the instrument cluster tachome-
ter (if equipped). Refer to Group 8E for tachometer
information.
TORQUE CONVERTER CLUTCH RELAYÐPCM
OUTPUT
ALL 2.5L 4 CYL. WITH 3-SPEED AUTO. TRANS
4.0L 6 CYL. YJ MODELS WITH 3-SPEED AUTO.
TRANS
The transmission mounted torque converter clutch
(TCC) solenoid is used to control the torque con-
verter. The solenoid is controlled through the power-
train control module (PCM) and by the TCC relay.
This relay is used only on vehicles equipped with a
3-speed automatic transmission.
An electrical output signal is sent from the PCM to
the TCC relay after the PCM receives information
from the vehicle speed, MAP, throttle position and
engine coolant temperature sensors. After the TCC
relay receives this necessary information, it will send
a signal to the torque converter clutch solenoid to
control the torque converter.
On YJ models the TCC relay is located in the en-
gine compartment, on the cowl panel and near the
battery (Fig. 24). On XJ models the TCC relay is lo-
cated in the power distribution center (PDC) (Fig.
23).
OPEN LOOP/CLOSED LOOP MODES OF
OPERATION
As input signals to the powertrain control module
(PCM) change, the PCM adjusts its response to the
output devices. For example, the PCM must calculate
different injector pulse width and ignition timing for
idle than it does for wide open throttle (WOT). There
are several different modes of operation that deter-
mine how the PCM responds to the various input sig-
nals.
MODES
²Open Loop
²Closed Loop
During Open Loop modes, the powertrain control
module (PCM) receives input signals and responds
only according to preset PCM programming. Input
from the oxygen (O2S) sensor is not monitored dur-
ing Open Loop modes.
During Closed Loop modes, the PCM will monitor
the oxygen (O2S) sensor input. This input indicates
to the PCM whether or not the calculated injector
pulse width results in the ideal air-fuel ratio. This
ratio is 14.7 parts air-to-1 part fuel. By monitoring
the exhaust oxygen content through the O2S sensor,
the PCM can fine tune the injector pulse width. This
is done to achieve optimum fuel economy combined
with low emission engine performance.
The fuel injection system has the following modes
of operation:
²Ignition switch ON
²Engine start-up (crank)
²Engine warm-up
²Idle
²Cruise
²Acceleration
²Deceleration
²Wide open throttle (WOT)
²Ignition switch OFF
The ignition switch On, engine start-up (crank),
engine warm-up, acceleration, deceleration and wide
open throttle modes are Open Loop modes. The idle
and cruise modes, (with the engine at operating tem-
perature) are Closed Loop modes.
IGNITION SWITCH (KEY-ON) MODE
This is an Open Loop mode. When the fuel system
is activated by the ignition switch, the following ac-
tions occur:
²The powertrain control module (PCM) pre-posi-
tions the idle air control (IAC) motor.
²The PCM determines atmospheric air pressure
from the MAP sensor input to determine basic fuel
strategy.
²The PCM monitors the engine coolant temperature
sensor input. The PCM modifies fuel strategy based
on this input.
Fig. 24 TCC Relay LocationÐYJ Models
JFUEL SYSTEM 14 - 27
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tle body. Fuel is sprayed into the manifold by the fuel
injectors. The throttle body is mounted on the intake
manifold. It contains an air control passage (Fig. 26)
controlled by an Idle Air Control (IAC) motor. The air
control passage is used to supply air for idle condi-
tions. A throttle valve (plate) is used to supply air for
above idle conditions.
The throttle position sensor (TPS) and idle air con-
trol (IAC) motor are attached to the throttle body.
The accelerator pedal cable, speed control cable and
transmission control cable (when equipped) are con-
nected to the throttle arm.
A (factory adjusted) set screw is used to mechani-
cally limit the position of the throttle body throttle
plate.Never attempt to adjust the engine idle
speed using this screw.All idle speed functions are
controlled by the PCM.
FUEL RAIL
The fuel rail supplies fuel to the injectors and is
mounted to the intake manifold (Fig. 27). The fuelpressure regulator is attached to the rail and the fuel
pressure test port is integral with the rail. The fuel
rail is not repairable.
FUEL PRESSURE REGULATOR
The fuel pressure regulator (Fig. 28) is a mechani-
cal device that is not controlled by the powertrain
control module (PCM).
The fuel pressure regulator used is a vacuum bal-
anced, nonadjustable type. The regulator is mounted
on the output end of the fuel rail and is connected to
intake manifold vacuum. The fuel return tube (to the
fuel tank) is connected to the fuel pressure regulator.
The regulator is calibrated to maintain fuel system
pressure at approximately 214 kPa (31 psi). This is
with vacuum applied while the engine is at idle. Fuel
pressure will be 55-69 kPa (8-10 psi) higher if vac-
uum is not applied to the regulator.
The pressure regulator contains a diaphragm, cali-
brated spring and a fuel return valve (Fig. 29). Fuel
pressure operates on one side of the regulator, while
spring pressure and intake manifold vacuum operate
on the other side. Spring pressure on one side of the
Fig. 27 Fuel RailÐTypical
Fig. 28 Fuel Pressure RegulatorÐTypical
Fig. 25 Throttle BodyÐTypical
Fig. 26 Idle Air Control Passage
14 - 30 FUEL SYSTEMJ
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diaphragm tries to force the return valve closed. Fuel
pressure on other side of diaphragm, with assistance
from manifold vacuum on spring side of diaphragm,
act against spring pressure to open the return valve.
System fuel pressure is the amount of fuel pressure
required to force against spring pressure and unseat
the return valve.
Without vacuum applied to the spring side of the
regulator, the spring is calibrated to open the fuel re-
turn outlet. This happens when the pressure differen-
tial between the fuel injectors and the intake
manifold reaches approximately 269 kPa (39 psi).
Since manifold vacuum varies with engine operating
conditions, the amount of vacuum applied to the
spring side of the diaphragm varies. For this reason,
fuel pressure varies, depending upon intake manifold
vacuum. With low vacuum, such as during wide open
throttle conditions, minimal vacuum assistance is
available. Full spring pressure is exerted to seal the
fuel outlet. This causes the system pressure to in-
crease. With high vacuum, such as at engine idle or
during vehicle deceleration, fuel pressure on one side
of the diaphragm is balanced by intake manifold
pressure. This is done on the spring side of the dia-
phragm and results in lower system fuel pressure.
Fig. 29 Fuel Pressure Regulator OperationÐTypical
JFUEL SYSTEM 14 - 31
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(8) Verify that crankcase ventilation (CCV) fresh
air hose is firmly connected to cylinder head and air
cleaner covers (Figs. 11 or 12).(9) Verify that vacuum hose is firmly connected to
fuel pressure regulator and manifold fitting (Figs. 13
or 14).
Fig. 9 Generator Connector and Output Wire
ConnectionsÐTypical
Fig. 10 System Ground ConnectionsÐTypical
Fig. 11 CCV SystemÐ2.5L Engine
Fig. 12 CCV SystemÐ4.0L Engine
Fig. 13 Pressure Regulator Vacuum HoseÐ2.5L
Engine
Fig. 14 Pressure Regulator Vacuum HoseÐ4.0L
Engine
14 - 34 FUEL SYSTEMJ
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(10) Inspect fuel tube quick-connect fitting-to-fuel
rail connections (Fig. 15).
(11) Verify that hose connections to all ports of
vacuum fittings on intake manifold are tight and not
leaking.
(12) Inspect accelerator cable, transmission throt-
tle cable (if equipped) and cruise control cable con-
nections (if equipped). Check their connections to the
throttle arm of throttle body for any binding or re-
strictions (Fig. 16).
(13) If equipped with vacuum brake booster, verify
that vacuum booster hose is firmly connected to fit-
ting on intake manifold. Also check connection to
brake vacuum booster (Fig. 17).
(14) On XJ models equipped with 4.0L engine and
A/C, verify that auxiliary cooling fan wire connector
is firmly connected to harness (Fig. 18).
(15) Inspect the air cleaner inlet and air filter ele-
ment for restrictions.
(16) Inspect radiator grille area, radiator fins and
air conditioning condenser for restrictions.(17) Verify that intake manifold air temperature
sensor wire connector is firmly connected to harness
connector (Figs. 19 or 20).
(18) Inspect engine ground strap connections at
dash panel and rear cylinder head bolt (Fig. 21).
(19) Verify that MAP sensor electrical connector is
firmly connected to MAP sensor (Fig. 22). Verify that
vacuum hose is firmly connected to MAP sensor and
to the intake manifold.
(20) Verify that fuel injector wire harness connec-
tors are firmly connected to the fuel injectors in the
correct order. Each harness connector is tagged with
the number of its corresponding fuel injector (Fig.
23).
Fig. 15 Fuel Supply TubeÐTypical
Fig. 16 Throttle Body CablesÐTypical
Fig. 17 Brake Vacuum Booster HoseÐTypical
Fig. 18 Auxiliary Cooling Fan ConnectorÐXJ with
4.0L Engine
JFUEL SYSTEM 14 - 35
Page 126 of 1770

harness connector terminal-2 and the sensor connec-
tor terminal. Also test terminal-4 to the sensor con-
nector terminal. Repair the wire harness as
necessary if the resistance is greater than 1 ohm.
FUEL PUMP RELAY TESTING
For testing this relay, refer to RelaysÐOperation/
Testing in this section of the group.
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
TEST
To perform a complete test of the MAP sensor and
its circuitry, refer to DRB scan tool and appropriate
Powertrain Diagnostics Procedures manual. To test
the sensor only, refer to the following:
Inspect the MAP sensor vacuum hose connections
at the throttle body and sensor. Repair as necessary.
CAUTION: When testing, do not remove the electri-
cal connector from MAP sensor (Fig. 37). Be sure
that the MAP sensor harness wires are not dam-
aged by the test meter probes.Test the MAP sensor output voltage at the MAP
sensor connector between terminals A and B (as
marked on the sensor body) (Fig. 38). With the igni-
tion switch ON and the engine OFF, output voltage
should be 4-to-5 volts. The voltage should drop to 1.5-
to-2.1 volts with a neutral-hot idle speed condition.
Test Powertrain Control Module (PCM) (termi-
nal-5) for the same voltage described above to verify
the wire harness condition. Repair as necessary.
Test MAP sensor supply voltage at sensor connec-
tor between terminals A and C (Fig. 38) with the ig-
nition ON and engine OFF. The voltage should be
approximately 5 volts (60.5V). Five volts (60.5V)
should also be at terminal-6 of the PCM wire harness
connector. Repair or replace the wire harness as nec-
essary.
Test the MAP sensor ground circuit at sensor con-
nector terminal-A (Fig. 38) and PCM connector ter-
minal-4. Repair the wire harness if necessary.
Test the MAP sensor ground circuit at the PCM
connector between terminal-4 and terminal-11 with
an ohmmeter. If the ohmmeter indicates an open cir-
cuit, inspect for a defective sensor ground connection.
Refer to Group 8W, Wiring for location of engine
grounds. If the ground connection is good, replace the
PCM. If terminal-4 has a short circuit to 12 volts,
correct this condition before replacing the PCM.
CRANKSHAFT POSITION SENSOR TEST
Refer to Group 8D, Ignition Systems for test proce-
dures.
Fig. 36 Air Temperature SensorÐ4.0L Engine
Fig. 37 MAP SensorÐTypical
Fig. 38 MAP Sensor Connector TerminalsÐTypical
14 - 44 FUEL SYSTEMJ
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87 and 30. Continuity should not be present between
terminals number 87A and 30.
(8) Disconnect jumper wires from relay and 12
Volt power source.
If continuity or resistance tests did not pass, re-
place relay. If tests passed, refer to Group 8W, Wir-
ing Diagrams for additional circuit information. Also
refer to the appropriate Powertrain Diagnostic Proce-
dures manual for operation of the DRB scan tool.
STARTER MOTOR RELAY TEST
Refer to Group 8A, Battery/Starting/Charging/Sys-
tem Diagnostics, for starter motor relay testing.
INJECTOR TEST
Disconnect the injector wire connector from the in-
jector. Place an ohmmeter on the injector terminals.
Resistance reading should be approximately 14.5
ohms61.2 ohms at 20ÉC (68ÉF). Proceed to following
Injector Diagnosis chart.
FUEL SYSTEM PRESSURE TEST
Refer to the Fuel Delivery System section of this
group. See Fuel System Pressure Test.
ON-BOARD DIAGNOSTICS (OBD)
The Powertrain Control Module (PCM) has been
programmed to monitor many different circuits of the
fuel injection system. If a problem is sensed in a
monitored circuit often enough to indicate an actual
problem, a Diagnostic Trouble Code (DTC) is stored.
The DTC will be stored in the PCM memory for
eventual display to the service technician. If the
problem is repaired or ceases to exist, the PCM can-
cels the DTC after 51 engine starts.
Certain criteria must be met for a diagnostic trou-
ble code (DTC) to be entered into PCM memory. The
criteria may be a specific range of engine rpm, en-
gine temperature and/or input voltage to the PCM.
It is possible that a DTC for a monitored circuit
may not be entered into memory even though a mal-
function has occurred. This may happen because one
of the DTC criteria for the circuit has not been met.
Example: assume that one of the criteria for the
MAP sensor circuit is that the engine must be oper-
ating between 750 and 2000 rpm to be monitored for
a DTC. If the MAP sensor output circuit shorts to
ground when the engine rpm is above 2400 rpm, a 0
volt input will be seen by the PCM. A DTC will not
be entered into memory because the condition does
not occur within the specified rpm range.
A DTC indicates that the powertrain control mod-
ule (PCM) has recognized an abnormal signal in a
circuit or the system. A DTC may indicate the result
of a failure, but never identify the failed component
directly.There are several operating conditions that the
PCM does not monitor and set a DTC for. Refer to
the following Monitored Circuits and Non-Monitored
Circuits in this section.
MONITORED CIRCUITS
The powertrain control module (PCM) can detect
certain problems in the fuel injection system.
Open or Shorted Circuit- The PCM can deter-
mine if sensor output (which is the input to PCM) is
within proper range. It also determines if the circuit
is open or shorted.
Output Device Current Flow- The PCM senses
whether the output devices are hooked up.
If there is a problem with the circuit, the PCM
senses whether the circuit is open, shorted to ground
(-), or shorted to (+) voltage.
Oxygen Sensor- The PCM can determine if the
oxygen sensor is switching between rich and lean.
This is, once the system has entered Closed Loop. Re-
fer to Open Loop/Closed Loop Modes Of Operation in
the Component Description/System Operation section
for an explanation of Closed (or Open) Loop opera-
tion.
NON-MONITORED CIRCUITS
The PCM does not monitor the following circuits,
systems or conditions that could have malfunctions
that result in driveability problems. A Diagnostic
Trouble Code (DTC) may not be displayed for these
conditions.
Fuel Pressure: Fuel pressure is controlled by the
vacuum assisted fuel pressure regulator. The PCM
cannot detect a clogged fuel pump inlet filter, clogged
in-line fuel filter, or a pinched fuel supply or return
line. However, these could result in a rich or lean
condition causing an oxygen sensor DTC to be stored
in the PCM.
Secondary Ignition Circuit: The PCM cannot
detect an inoperative ignition coil, fouled or worn
spark plugs, ignition cross firing, or open circuited
spark plug cables.
Engine Timing: The PCM cannot detect an incor-
rectly indexed timing chain, camshaft sprocket or
crankshaft sprocket. The PCM also cannot detect an
incorrectly indexed distributor. However, these could
result in a rich or lean condition causing an oxygen
sensor DTC to be stored in the PCM.
Cylinder Compression: The PCM cannot detect
uneven, low, or high engine cylinder compression.
Exhaust System: The PCM cannot detect a
plugged, restricted or leaking exhaust system.
Fuel Injector Malfunctions: The PCM cannot de-
termine if the fuel injector is clogged, or the wrong
injector is installed. However, these could result in a
rich or lean condition causing an oxygen sensor DTC
to be stored in the PCM.
14 - 48 FUEL SYSTEMJ
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Excessive Oil Consumption: Although the PCM
monitors exhaust stream oxygen content through ox-
ygen sensor (closed loop), it cannot determine exces-
sive oil consumption.
Throttle Body Air Flow: The PCM cannot detect
a clogged or restricted air cleaner inlet or air filter
element.
Evaporative System: The PCM will not detect a
restricted, plugged or loaded EVAP canister.
Vacuum Assist: Leaks or restrictions in the vac-
uum circuits of vacuum assisted engine control sys-
tem devices are not monitored by the PCM. However,
a vacuum leak at the MAP sensor will be monitored
and a diagnostic trouble code (DTC) will be gener-
ated by the PCM.
Powertrain Control Module (PCM) System
Ground: The PCM cannot determine a poor system
ground. However, a DTC may be generated as a re-
sult of this condition.
Powertrain Control Module (PCM) Connector
Engagement: The PCM cannot determine spread or
damaged connector pins. However, a DTC may be
generated as a result of this condition.
HIGH AND LOW LIMITS
The powertrain control module (PCM) compares in-
put signal voltages from each input device. It will es-
tablish high and low limits that are programmed into
it for that device. If the input voltage is not within
specifications and other Diagnostic Trouble Code
(DTC) criteria are met, a DTC will be stored in mem-
ory. Other DTC criteria might include engine rpm
limits or input voltages from other sensors or
switches. The other inputs might have to be sensed
by the PCM when it senses a high or low input volt-
age from the control system device in question.
ACCESSING DIAGNOSTIC TROUBLE CODES
A stored Diagnostic Trouble Code (DTC) can be dis-
played by cycling the ignition key On-Off-On-Off-On
within three seconds and observing the Malfunction
Indicator Lamp. This lamp was formerly referred to
as the Check Engine Lamp. The lamp is located on
the instrument panel.
They can also be displayed through the use of the
Diagnostic Readout Box (DRB) scan tool. The DRB
scan tool connects to the data link connector in the
engine compartment (Figs. 45 or 46). For operation of
the DRB, refer to the appropriate Powertrain Diag-
nostic Procedures service manual.
EXAMPLES:
²If the lamp flashes 4 times, pauses and flashes 1
more time, a flashing Diagnostic Trouble Code (DTC)
number 41 is indicated.
²If the lamp flashes 4 times, pauses and flashes 6
more times, a flashing Diagnostic Trouble Code
(DTC) number 46 is indicated.After any stored DTC information has been ob-
served, the display will end with a flashing DTC
number 55. This will indicate the end of all stored
information.
Refer to the Diagnostic Trouble Code (DTC) charts
for DTC identification.
If the problem is repaired or ceases to exist, the
Powertrain Control Module (PCM) cancels the DTC
after 51 engine starts.
Diagnostic Trouble Codes indicate the results of a
failure, but never identify the failed component di-
rectly.
The circuits of the data link connector are shown
in (Fig. 47).
ERASING TROUBLE CODES
After the problem has been repaired, use the DRB
scan tool to erase a Diagnostic Trouble Code (DTC).
Refer to the appropriate Powertrain Diagnostic Pro-
cedures service manual for operation of the DRB
scan tool.
Fig. 45 Data Link ConnectorÐYJ ModelsÐTypical
Fig. 46 Data Link ConnectorÐXJ ModelsÐTypical
14 - 50 FUEL SYSTEMJ
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DIAGNOSTIC TROUBLE CODE DESCRIPTIONSÐCONTINUED
Diagnostic
Trouble
CodeDRB Scan Tool
DisplayDescription of Diagnostic Trouble Code
23**..........Intake Air Temp Sensor
Voltage LowIntake air temperature sensor input below the minimum acceptable voltage.
or
Intake Air Temp Sensor
Voltage HighIntake air temperature sensor input above the maximum acceptable voltage.
24**..........Throttle Position Sensor
Voltage HighThrottle position sensor input above the maximum acceptable voltage.
or
Throttle Position Sensor
Voltage LowThrottle position sensor input below the minimum acceptable voltage.
25**..........Idle Air Control Motor
CircuitsA shorted condition detected in one or more of the idle air control motor
circuits.
27* ..........Injector #1 Control Circuit Injector #1 output driver does not respond properly to the control signal.
or
Injector #2 Control Circuit Injector #2 output driver does not respond properly to the control signal.
or
Injector #3 Control Circuit Injector #3 output driver does not respond properly to the control signal.
or
Injector #4 Control Circuit Injector #4 output driver does not respond properly to the control signal.
or
Injector #5 Control Circuit Injector #5 output driver does not respond properly to the control signal.
or
Injector #6 Control Circuit Injector #6 output driver does not respond properly to the control signal.
33* .......... A/CClutch Relay Circuit An open or shorted condition detected in the A/C clutch relay circuit.
34* ..........Speed Control Solenoid
CircuitsAn open or shorted condition detected in the Speed Control vacuum or vent
solenoid circuits.
or
Speed Control Switch
Always LowSpeed Control switch input below the minimum acceptable voltage.
or
Speed Control Switch
Always HighSpeed Control switch input above the maximum acceptable voltage.
35* (XJ Only).... RadFanControl Relay
CircuitsAn open or shorted condition detected in the radiator fan relay circuit.
* Check Engine Lamp will not illuminate at all times if this Diagnostic Trouble Code was recorded. Cycle Ignition key as
described in manual and observe code flashed by Check Engine lamp.
** Check Engine Lamp will illuminate during engine operation if this Diagnostic Trouble Code was recorded.
14 - 52 FUEL SYSTEMJ
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INSTALLATION
(1) Install the fuel injector(s) into the fuel rail as-
sembly and install retaining clip(s).
(2) Install fuel rail. Refer to Fuel Rail Installation
in this section.
(3) Start engine and check for fuel leaks.
FUEL PUMP MODULE
Refer to the Fuel Delivery System section of this
group for removal/installation procedures.
FUEL PUMP RELAY
The Fuel Pump relay is located in the Power Dis-
tribution Center (PDC) (Figs. 1 or 2). For location of
this relay within the PDC, refer to label on PDC
cover.
FUEL RAIL ASSEMBLY
REMOVAL
WARNING: THE FUEL SYSTEM IS UNDER CON-
STANT FUEL PRESSURE (EVEN WITH THE ENGINE
OFF) OF APPROXIMATELY 131-269 KPA (19-39
PSI). THIS PRESSURE MUST BE RELEASED BE-
FORE SERVICING THE FUEL RAIL.
(1) Remove fuel tank filler tube cap.
(2) Disconnect the negative battery cable from bat-
tery.
(3) Perform the Fuel System Pressure Release Pro-
cedure as described in the Fuel Delivery System sec-
tion of this Group.
(4) Remove and numerically attach a tag (if fuel
injector is not already tagged), the injector harness
connectors. Do this at each injector (Fig. 7).
(5) Disconnect vacuum line from fuel pressure reg-
ulator (Fig. 7).
(6) Disconnect fuel supply line from fuel rail and
the fuel return line from fuel pressure regulator (Fig.7). Refer to Fuel Tubes/Lines/Hoses and Clamps, or
Quick-Connect Fittings. These can both be found in
the Fuel Delivery section of this group.
(7) Remove fuel rail mounting bolts.
On models with automatic transmissions, it may be
necessary to remove automatic transmission throttle
line pressure cable (and bracket). This will aid in fuel
rail assembly removal.
(8) Remove fuel rail by gently rocking until all the
fuel injectors are out of the intake manifold.
INSTALLATION
(1) Position tips of all fuel injectors into the corre-
sponding injector bore in the intake manifold. Seat
injectors into manifold.
(2) Tighten fuel rail mounting bolts to 27 Nzm (20
ft. lbs.) torque.
(3) Connect injector harness connectors to appro-
priate (tagged) injector.
(4) Connect both fuel lines to fuel rail.
(5) Connect vacuum supply line to fuel pressure
regulator.
(6) Install protective cap to pressure test port fit-
ting.
(7) Install fuel tank cap.
(8) Connect negative battery cable to battery.
(9) Start engine and check for fuel leaks.
FUEL SYSTEM PRESSURE RELEASE PROCEDURE
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE (EVEN WITH THE ENGINE OFF)
OF APPROXIMATELY 100 KPA (14.5 PSI). BEFORE
SERVICING THE FUEL PUMP, FUEL LINES, FUEL
FILTER OR FUEL INJECTOR, THE FUEL SYSTEM
PRESSURE MUST BE RELEASED.
Refer to the Fuel Delivery System section of this
group. See Fuel Pressure Release procedure.
FUEL TANKS
Refer to the Fuel Tank section of this group for re-
moval/installation procedures.
FUEL TANK PRESSURE RELIEF/ROLLOVER VALVE
Refer to the Fuel Tank section of this group for re-
moval/installation procedures.
FUEL TUBES/LINES/HOSES AND CLAMPS
Refer to the Fuel Delivery System section of this
group for removal/installation procedures. Also refer
to Quick-Connect Fittings in the Fuel Delivery sec-
tion of this group.
IDLE AIR CONTROL (IAC) MOTOR
The IAC motor is mounted to the throttle body ad-
jacent to the throttle position sensor (Fig. 8).
Fig. 7 Fuel Injector HarnessÐTypical
14 - 56 FUEL SYSTEMJ