Engine 3.7L JEEP LIBERTY 2002 KJ / 1.G Workshop Manual

(5) Remove the two nuts securing the wire loom
behind the pump bracket.
(6) Remove the three bolts securing the pump to
the bracket thru the holes in the pulley. (Fig. 4)
(7) Remove the pump from the vehicle.
INSTALLATION
INSTALLATION - 3.7L
(1) Install the pump to the vehicle.(2) Install the three bolts securing the pump to the
engine. (Fig. 3) Tighten the bolts to 47 N´m (35
ft.lbs.).
(3) Install the power steering hoses.
(4) Install the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(5) Install the fan shroud
(6) Install the engine cooling fan (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - INSTALLA-
TION).
(7) Install the radiator crossmember (Refer to 23 -
BODY/EXTERIOR/RADIATOR CROSSMEMBER -
INSTALLATION).
(8) Refill the power steering fluid and check for
leaks (Refer to 19 - STEERING/PUMP - STANDARD
PROCEDURE).
INSTALLATION - 2.4L
(1) Install the pump to the vehicle.
(2) Install the three bolts securing the pump to the
engine. (Fig. 4) Tighten the bolts to 47 N´m (35
ft.lbs.).
(3) Install the two nuts securing the wire loom to
the pump bracket.
(4) Install the power steering pressure and supply
hoses.
(5) Install the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(6) Refill the power steering fluid and check for
leaks (Refer to 19 - STEERING/PUMP - STANDARD
PROCEDURE).
SPECIFICATIONS
TORQUE CHART
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Power Steering Pump
Bracket to Pump28 21 Ð
Power Steering Pump
Bracket to Engine47 35 Ð
Power Steering Pump
Flow Control Valve75 55 Ð
Power Steering Pump
Pressure Line28 21 Ð
Power Steering Pump
Pressure Line Bracket12 9 105
Fig. 4 POWER STEERING PUMP - 2.4L
1 - MOUNTING BOLTS
2 - PULLEY
KJPUMP 19 - 19
PUMP (Continued)

(6) Install the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(7) Install the fan shroud.
(8) Install the fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - INSTALLATION).
(9) Install the radiator crossmember (Refer to 23 -
BODY/EXTERIOR/RADIATOR CROSSMEMBER -
INSTALLATION).
(10) Refill the power steering fluid (Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE).
INSTALLATION - RETURN HOSE (GEAR TO THE
COOLER)
(1) Install the return hose to the vehicle. (Fig. 7)
(2) Install the return hose mounting bracket bolts
to the front cradle.
(3) Install the return hose at the cooler.
(4) Install the return hose at the gear 28 N´m (21
ft.lbs.).
(5) Install the serpentine belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(6) Install the fan shroud.
(7) Install the fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - INSTALLATION).
(8) Install the radiator crossmember (Refer to 23 -
BODY/EXTERIOR/RADIATOR CROSSMEMBER -
INSTALLATION).
(9) Refill the power steering fluid (Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE).
INSTALLATION - RETURN HOSE (RESERVOIR
TO THE COOLER)
(1) Install the return hose to the vehicle.
(2) Install the return hose to the pump reservoir.
(3) Install the return hose at the cooler.
(4) Refill the power steering fluid (Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE).
POWER STEERING PRESSURE
SWITCH
DESCRIPTION
A pressure sensing switch is used in the power
steering system. It is mounted on the high-pressure
steering hose. This switch will be used with both
2.4L and 3.7L engines.
OPERATION
The switch is used on both the 2.4L 4±cylinder and
3.7L V-6 engines.
The power steering pressure switch provides an
input to the Powertrain Control Module (PCM). This
input is provided during periods of high steering
pump load and low engine rpm; such as during park-
ing maneuvers. The PCM increases the idle speed
through the Idle Air Control (IAC) motor. This is
done to prevent the engine from stalling under the
increased load.
When steering pump pressure exceeds 3275 kPa  
690 kPa (475 psi   100 psi), the Normally Closed
(NC) switch will open and the PCM will increase the
engine idle speed. This will prevent the engine from
stalling.
When pump pressure drops to approximately 1379
kPa (200 psi), the switch circuit will re-close and
engine idle speed will return to its previous setting.
REMOVAL
The power steering pressure switch is installed in
the power steering high-pressure hose (Fig. 9).
(1) Remove the high pressure power steering
hose(Refer to 19 - STEERING/PUMP/HOSES -
REMOVAL).
(2) Disconnect electrical connector from power
steering pressure switch.
(3) Place a small container or shop towel beneath
switch to collect any excess fluid.
(4) Remove switch. Use back-up wrench on power
steering line to prevent line bending.
INSTALLATION
(1) Install power steering switch into power steer-
ing line. (Fig. 9)
(2) Tighten to 9.6 N´m (85 in. lbs.) torque.
Fig. 8 HIGH PRESSURE HOSE ASSEMBLY
1 - HIGH PRESSURE POWER STEERING HOSE
2 - MOUNTING BRACKET
3 - POWER STEERING PRESURE SWITCH
19 - 22 PUMPKJ
HOSES (Continued)

RESERVOIR
REMOVAL
REMOVAL - 3.7L
(1) Remove the power steering pump. (Refer to 19
- STEERING/PUMP - REMOVAL).
(2) Secure the pump in a holding fixture.
(3) Remove the retaining clips by prying the lock
tab upwards and tap the retaining clips off the pump
body. (Fig. 12)
(4) Remove the reservoir from the pump body.
REMOVAL - 2.4L
(1) Siphon out as much power steering fluid as
possible.
(2) Remove the power steering hoses.(3) Remove the bolt securing the reservoir to the
mounting bracket. (Fig. 13)
(4) Remove the reservoir.
INSTALLATION
INSTALLATION - 3.7L
(1) Install the reservoir to the pump body.
(2) Install the retaining clips to the pump and res-
ervoir.
(3) Install the pump to the engine. (Refer to 19 -
STEERING/PUMP - INSTALLATION).
(4) Refill the power steering fluid and check for
leaks (Refer to 19 - STEERING/PUMP - STANDARD
PROCEDURE).
INSTALLATION - 2.4L
(1) Install the reservoir to the mounting bracket.
(2) Install and tighten the bolt to
(3) Install the hoses.
(4) Refill the power steering fluid and check for
leaks (Refer to 19 - STEERING/PUMP - STANDARD
PROCEDURE). (Fig. 13)
Fig. 12 FLUID RESERVOIR
1 - FLUID RESERVOIR
2 - RETAINING CLIP
3 - PULLEY
4 - PUMP BODY
Fig. 13 FLUID RESERVOIR - 2.4L
19 - 24 PUMPKJ

A/C COMPRESSOR CLUTCH
DESCRIPTION - 3.7L and 2.4L
The compressor clutch assembly consists of a sta-
tionary electromagnetic coil, a rotor bearing and
rotor assembly, and a clutch plate (Fig. 1). The elec-
tromagnetic coil unit and the rotor bearing and rotor
assembly are each retained on the nose of the com-
pressor front housing with snap rings. The clutch
plate is keyed to the compressor shaft and secured
with a nut. These components provide the means to
engage and disengage the compressor from the
engine serpentine accessory drive belt.
OPERATION - 3.7L and 2.4L
When the clutch coil is energized, it magnetically
draws the clutch into contact with the rotor and
drives the compressor shaft. When the coil is not
energized, the rotor freewheels on the clutch rotor
bearing, which is part of the rotor. The compressor
clutch and coil are the only serviced parts on the
compressor.
The compressor clutch engagement is controlled by
several components: the A/C Heater mode control
switch, the A/C low pressure switch, the A/C high
pressure switch, the compressor clutch relay, and the
Powertrain Control Module (PCM). The PCM may
delay compressor clutch engagement for up to thirty
seconds. Refer to Electronic Control Modules for
more information on the PCM controls.
DIAGNOSIS AND TESTING - A/C COMPRESSOR
CLUTCH COIL
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information). The battery must
be fully-charged before performing the following
tests. Refer to Battery for more information.
(1) Connect an ammeter (0 to 10 ampere scale) in
series with the clutch coil terminal. Use a voltmeter
(0 to 20 volt scale) with clip-type leads for measuring
the voltage across the battery and the compressor
clutch coil.
(2) With the A/C Heater mode control switch in
any A/C mode, and the blower motor switch in the
lowest speed position, start the engine and run it at
normal idle.
(3) The compressor clutch coil voltage should read
within 0.2 volts of the battery voltage. If there is
voltage at the clutch coil, but the reading is not
within 0.2 volts of the battery voltage, test the clutch
coil feed circuit for excessive voltage drop and repair
as required. If there is no voltage reading at the
clutch coil, use a DRB IIItscan tool and (Refer to
Appropriate Diagnostic Information) for testing of the
compressor clutch circuit and PCM control. The fol-
lowing components must be checked and repaired as
required before you can complete testing of the clutch
coil:
²Fuses in the junction block and the Power Dis-
tribution Center (PDC)
²A/C heater mode control switch
²Compressor clutch relay
²A/C high pressure switch
²A/C low pressure switch
²Powertrain Control Module (PCM).
(4) The compressor clutch coil is acceptable if the
current draw measured at the clutch coil is 2.0 to 3.9
amperes with the electrical system voltage at 11.5 to
12.5 volts. This should only be checked with the work
area temperature at 21É C (70É F). If system voltage
is more than 12.5 volts, add electrical loads by turn-
ing on electrical accessories until the system voltage
drops below 12.5 volts.
(a) If the clutch coil current reading is four
amperes or more, the coil is shorted and should be
replaced.
(b) If the clutch coil current reading is zero, the
coil is open and should be replaced.
STANDARD PROCEDURE - A/C COMPRESSOR
CLUTCH BREAK-IN
After a new compressor clutch has been installed,
cycle the compressor clutch approximately twenty
times (five seconds on, then five seconds off). During
this procedure, set the A/C Heater control to the
Recirculation Mode, the blower motor switch in the
highest speed position, and the engine speed at 1500
Fig. 1 COMPRESSOR CLUTCH - TYPICAL
1 - CLUTCH PLATE
2 - NOT USED ON KJ
3 - ROTOR
4 - COIL
5 - CLUTCH SHIMS
6 - SNAP RING
7 - SNAP RING
24 - 12 CONTROLSKJ

INSTALLATION
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION) (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTION - REFRIGERANT HOSES/LINES/TUBES
PRECAUTIONS)
The compressor may be removed and repositioned
without disconnecting the refrigerant lines or dis-
charging the refrigerant system. Discharging is not
necessary if servicing the compressor clutch or clutch
coil, the engine, the cylinder head, or the generator.
NOTE: If a replacement compressor is being
installed, be certain to check the refrigerant oil
level. (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/REFRIGERANT OIL - STANDARD PRO-
CEDURE - REFRIGERANT OIL LEVEL) Use only
refrigerant oil of the type recommended for the
compressor in the vehicle. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING/REFRIGERANT OIL -
DESCRIPTION)(1) Install the compressor to the mounting bracket.
Tighten the three mounting bolts to 27 N´m (20 ft.
lbs.), (2.4L gasoline and 2.5L diesel engines only).
(2) On the 3.7L gasoline engine install and tighten
the bolts in the following sequence (Fig. 5):
²The number one bolt (rear) is hand tightened
first then tightened to 55 N´m (41 ft. lbs.)
²The number three bolt is then hand tightened
and torqued to 40 N´m ( 30 ft. lbs.)
²The number two bolt is also hand tightened and
torqued to 55 N´m ( 41 ft. lbs.)
(3) Remove the tape or plugs from all of the
opened refrigerant line fittings. Install the suction
and discharge line manifold to the compressor.
Tighten the fastener to 28 N´m (250 in. lbs.).(Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING/
SUCTION LINE - INSTALLATION) (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
DISCHARGE LINE - INSTALLATION)
(4) Install the serpentine drive belt(Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
Fig. 3 A/C COMPRESSOR - 3.7L ENGINE
1 - COMPRESSOR BOLT #1
2 - COMPRESSOR BOLT #2
3 - COMPRESSOR BOLT #3
4 - A/C COMPRESSOR
5 - A/C COMPRESSOR CLUTCH AND PULLEY
6 - COMPRESSOR MOUNT
Fig. 4 A/C COMPRESSOR - 2.5L DIESEL ENGINE
1 - SUCTION LINE MOUNTING NUT
2- SUCTION LINE MOUNTING CLIP
3- SUCTION LINE
4- MOUNTING SCREW FOR SUCTION LINE
5- SUCTION LINE MOUNTING FLANG
6- MOUNTING SCREW FOR DISCHARGE LINE
7- DISCHARGE LINE MOUNTING FLANG
8- A/C PRESSURE SENSOR
9- A/C DISCHARGE LINE
10- A/C COMPRESSOR ASSEMBLY
11- A/C DISCHARGE LINE SERVICE PORT
24 - 44 PLUMBINGKJ
A/C COMPRESSOR (Continued)

(5) Plug in the compressor clutch coil wire harness
connector.
(6) Connect the battery negative cable.
(7) Evacuate the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE)
(8) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
A/C CONDENSER
DESCRIPTION
The condenser is located in the air flow in front of
the engine cooling radiator. The condenser is a heat
exchanger that allows the high-pressure refrigerant
gas being discharged by the compressor to give up its
heat to the air passing over the condenser fins.
OPERATION
When the refrigerant gas gives up its heat, it con-
denses. When the refrigerant leaves the condenser, it
has become a high-pressure liquid refrigerant. Thevolume of air flowing over the condenser fins is crit-
ical to the proper cooling performance of the air con-
ditioning system. Therefore, it is important that
there are no objects placed in front of the radiator
grille openings in the front of the vehicle or foreign
material on the condenser fins that might obstruct
proper air flow. Also, any factory-installed air seals or
shrouds must be properly reinstalled following radia-
tor or condenser service.
The condenser cannot be repaired and, if faulty or
damaged, it must be replaced.
REMOVAL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
(1) Disconnect and isolate the battery negative
cable.
(2) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY)
(3) Disconnect the discharge line refrigerant line
fitting at the condenser inlet. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE - A/C LINE COUPLERS)
Install plugs in, or tape over all of the opened refrig-
erant line fittings.
(4) Disconnect the liquid line (Left-Hand Drive) or
liquid line jumper (Right-Hand Drive) refrigerant
line fitting at the condenser outlet. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - A/C LINE COUPLERS)
Install plugs in, or tape over all of the opened refrig-
erant line fittings.
(5) Remove the radiator and the condenser from
the vehicle as a unit. Refer to Cooling for the proce-
dures.
(6) Remove the two nuts that secure the condenser
studs to the upper brackets of the radiator (Fig. 6).
(7) Slide the condenser down from the radiator far
enough for the condenser studs to clear the upper
radiator bracket holes, and for the lower condenser
bracket holes to clear the dowel pins on the bottom of
the radiator.
(8) Remove the condenser from the radiator.
Fig. 5 A/C COMPRESSOR - 3.7L ENGINE
1 - COMPRESSOR BOLT #1
2 - COMPRESSOR BOLT #2
3 - COMPRESSOR BOLT #3
4 - A/C COMPRESSOR
5 - A/C COMPRESSOR CLUTCH AND PULLEY
6 - COMPRESSOR MOUNT
KJPLUMBING 24 - 45
A/C COMPRESSOR (Continued)

SPECIFICATIONS
TORQUE
DESCRIPTION N-m Ft. Lbs. In. Lbs.
Accelerator Pedal Bracket
Mounting Nuts12 - 105
Crankshaft Position Sensor - 2.4L 28 21 -
Crankshaft Position Sensor - 3.7L 28 21 -
Camshaft Position Sensor - 2.4L 12 - 106
Camshaft Position Sensor - 3.7L 12 - 106
Engine Coolant Temperature
Sensor11 - 9 6
EVAP Canister-to-Body Bolts 48 35 -
EVAP Canister-to-Canis. Bracket
Bolt/Nut11 - 100
Fuel Filler Hose Clamp at Tank 3 - 30
Fuel Filler Housing-to-Body
Screws2-17
Fuel Filter Mounting Nut at Tank 5.5 - 49
Fuel Pump Module Access Plate
Nuts3-26
Fuel Rail Mounting Bolts - 3.7L 11 - 100
Fuel Rail Mounting Bolts - 2.4L 28 - 250
Fuel Tank Heat Sheild Nuts 5.5 - 49
Fuel Tank Mounting Strap Bolts 61 45 -
Fuel Tank Skid Plate and Trailer
Hitch88 65 -
IAC Motor Mounting Screws 7 - 60
Leak Detection Pump Mounting
Bracket-to-Fuel Tank Nuts5.5 - 49
Leak Detection Pump-to-Bracket
Nuts1.2 - 11
Map Sensor Mounting Screws 3 - 25
PCM-to-Mounting Bracket
Mounting Screws4-35
Power Steering Pressure Switch 14-22 - 124-195
TPS Mounting Screws 7 - 60
Throttle Body Mounting Bolts 11 - 100
Oxygen Sensors 30 22 -
25 - 26 EVAPORATIVE EMISSIONSKJ
EVAPORATIVE EMISSIONS (Continued)

(4) Carefully install vapor/vacuum lines to LDP,
and install hose to LDP filter.The vapor/vacuum
lines and hoses must be firmly connected.
Check the vapor/vacuum lines at the LDP, LDP
filter and EVAP canister duty cycle purge sole-
noid for damage or leaks. If a leak is present, a
Diagnostic Trouble Code (DTC) may be set.
ORVR
DESCRIPTION
The ORVR (On-Board Refueling Vapor Recovery)
system consists of a unique fuel tank, flow manage-
ment valve, fluid control valve, one-way check valve
and vapor canister (Fig. 1).
OPERATION
The ORVR (On-Board Refueling Vapor Recovery)
system is used to remove excess fuel tank vapors.
This is done while the vehicle is being refueled. Cer-
tain ORVR components can be found in (Fig. 1).
Fuel flowing into the fuel filler tube (approx. 1º
I.D.) creates an aspiration effect drawing air into the
fuel fill tube. During refueling, the fuel tank is
vented to the EVAP canister to capture escaping
vapors. With air flowing into the filler tube, there are
no fuel vapors escaping to the atmosphere. Once the
refueling vapors are captured by the EVAP canister,the vehicle's computer controlled purge system draws
vapor out of the canister for the engine to burn. The
vapor flow is metered by the purge solenoid so that
there is no, or minimal impact on driveability or
tailpipe emissions.
As fuel starts to flow through the fuel fill tube, it
opens the normally closed check valve and enters the
fuel tank. Vapor or air is expelled from the tank
through the control valve and on to the vapor canis-
ter. Vapor is absorbed in the EVAP canister until
vapor flow in the lines stops. This stoppage occurs
following fuel shut-off, or by having the fuel level in
the tank rise high enough to close the control valve.
This control valve contains a float that rises to seal
the large diameter vent path to the EVAP canister.
At this point in the refueling process, fuel tank pres-
sure increases, the check valve closes (preventing liq-
uid fuel from spiting back at the operator), and fuel
then rises up the fuel filler tube to shut off the dis-
pensing nozzle.
PCV VALVE
DESCRIPTION
2.4L
The 2.4L 4-cylinder engine is equipped with a
closed crankcase ventilation system and a Positive
Crankcase Ventilation (PCV) valve.
This system consists of:
²a PCV valve attached to the left/front side of the
valve cover (Fig. 5). It is secured with 1 bolt. An
o-ring is used to seal valve to valve cover (Fig. 6).
²the air cleaner housing
²tubes and hoses to connect the system compo-
nents.
3.7L
The 3.7L V-6 engine is equipped with a closed
crankcase ventilation system and a Positive Crank-
case Ventilation (PCV) valve.
This system consists of:
²a PCV valve mounted to the oil filler housing
(Fig. 7). The PCV valve is sealed to the oil filler
housing with an o-ring.
²the air cleaner housing
²two interconnected breathers threaded into the
rear of each cylinder head (Fig. 8).
²tubes and hoses to connect the system compo-
nents.
Fig. 4 LDP ELECTRICAL CONNECTOR
1 - LEAK DETECTION PUMP (LDP)
2 - ELECTRICAL CONNECTOR
3 - FUEL FILTER
KJEVAPORATIVE EMISSIONS 25 - 29
LEAK DETECTION PUMP (Continued)

Fig. 5 PCV VALVE LOCATION - 2.4L
1 - P C V VA LV E
2 - HOSE
3 - MOUNTING BOLT
4 - VALVE COVER (LEFT SIDE)
Fig. 6 PCV VALVE AND O-RING - 2.4L
1 - P C V VA LV E
2 - O-RING
3 - MOUNTING BOLT
Fig. 7 PCV VALVE - 3.7L
1 - O-RING
2 - LOCATING TABS
3 - CAM LOCK
4 - OIL FILLER TUBE
5 - PCV LINE/HOSE
6 - P C V VA LV E
Fig. 8 CRANKCASE BREATHERS (2) - 3.7L
1 - CRANKCASE BREATHERS (2)
2 - REAR OF ENGINE
25 - 30 EVAPORATIVE EMISSIONSKJ
PCV VALVE (Continued)

OPERATION
The PCV system operates by engine intake mani-
fold vacuum. Filtered air is routed into the crankcase
through the air cleaner hose and crankcase breath-
er(s) (if used). The metered air, along with crankcase
vapors, are drawn through the PCV valve and into a
passage in the intake manifold. The PCV system
manages crankcase pressure and meters blow-by
gases to the intake system, reducing engine sludge
formation.
The PCV valve contains a spring loaded plunger.
This plunger meters the amount of crankcase vapors
routed into the combustion chamber based on intake
manifold vacuum.
TYPICALPCV valves are shown in (Fig. 9), (Fig.
10) and (Fig. 11).
When the engine is not operating, or during an
engine pop-back, the spring forces the plunger back
against the seat (Fig. 9). This will prevent vapors
from flowing through the valve.
During periods of high manifold vacuum, such as
idle or cruising speeds, vacuum is sufficient to com-
pletely compress spring. It will then pull the plunger
to the top of the valve (Fig. 10). In this position there
is minimal vapor flow through the valve.
During periods of moderate manifold vacuum, the
plunger is only pulled part way back from inlet. This
results in maximum vapor flow through the valve
(Fig. 11).
DIAGNOSIS AND TESTING - PCV VALVE
3.7L
(1) Disconnect PCV line/hose (Fig. 7) by discon-
necting rubber connecting hose at PCV valve fitting.
(2) Remove PCV valve at oil filler tube by rotating
PCV valve downward until locating tabs have been
freed at cam lock (Fig. 7). After tabs have cleared,
pull valve straight out from filler tube.To prevent
damage to PCV valve locating tabs, valve must
be pointed downward for removal. Do not force
valve from oil filler tube.
(3) After valve is removed, check condition of valve
o-ring (Fig. 7). Also, PCV valve should rattle when
shaken.
(4) Reconnect PCV valve to its connecting line/
hose.
(5) Start engine and bring to idle speed.
(6) If valve is not plugged, a hissing noise will be
heard as air passes through valve. Also, a strong vac-
uum should be felt with a finger placed at valve
inlet.
(7) If vacuum is not felt at valve inlet, check line/
hose for kinks or for obstruction. If necessary, clean
out intake manifold fitting at rear of manifold. Do
this by turning a 1/4 inch drill (by hand) through the
fitting to dislodge any solid particles. Blow out the
fitting with shop air. If necessary, use a smaller drill
to avoid removing any metal from the fitting.
(8)Do not attempt to clean the old PCV valve.
(9) Return PCV valve back to oil filler tube by
placing valve locating tabs (Fig. 7) into cam lock.
Press PCV valve in and rotate valve upward. A slight
click will be felt when tabs have engaged cam lock.
Valve should be pointed towards rear of vehicle.
(10) Connect PCV line/hose and connecting rubber
hose to PCV valve.
(11) Disconnect rubber hose from fresh air fitting
at air cleaner resonator box. Start engine and bring
to idle speed. Hold a piece of stiff paper (such as a
parts tag) loosely over the opening of the discon-
nected rubber hose.
(12) The paper should be drawn against the hose
opening with noticeable force. This will be after
allowing approximately one minute for crankcase
pressure to reduce.
Fig. 9 Engine Off or Engine Pop-BackÐNo Vapor
Flow
Fig. 10 High Intake Manifold VacuumÐMinimal
Vapor Flow
Fig. 11 Moderate Intake Manifold VacuumÐ
Maximum Vapor Flow
KJEVAPORATIVE EMISSIONS 25 - 31
PCV VALVE (Continued)