2003 JEEP GRAND CHEROKEE pump

OIL PUMP
REMOVAL
(1) Remove the oil pan and pick-up tube (Refer to
9 - ENGINE/LUBRICATION/OIL PAN - REMOVAL).
(2) Remove the timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL).
(3) Remove the timing chains and tensioners
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT/CHAIN AND SPROCKETS - REMOVAL).
(4) Remove the four bolts, primary timing chain
tensioner and the oil pump.
DISASSEMBLY
(1) Remove oil pump cover screws and lift off cover
plate.
(2) Remove pump inner and outer rotors.
NOTE: Once the oil pressure relief valve, cup plug,
and pin are removed, the pump assembly must be
replaced.
(3) If it is necessary to remove the pressure relief
valve, drive the roll pin from pump housing and
remove cup plug, spring and valve.
CLEANING
(1) Wash all parts in a suitable solvent.
INSPECTION
CAUTION: Oil pump pressure relief valve and
spring should not be removed from the oil pump. If
these components are disassembled and or
removed from the pump the entire oil pump assem-
bly must be replaced.
(1) Clean all parts thoroughly. Mating surface of
the oil pump housing should be smooth. If the pump
cover is scratched or grooved the oil pump assembly
should be replaced.
(2) Lay a straight edge across the pump cover sur-
face (Fig. 97). If a 0.025 mm (0.001 in.) feeler gauge
can be inserted between the cover and the straight
edge the oil pump assembly should be replaced.
(3) Measure the thickness of the outer rotor (Fig.
98). If the outer rotor thickness measures at 12.005
mm (0.472 in.) or less the oil pump assembly must be
replaced.(4) Measure the diameter of the outer rotor. If the
outer rotor diameter measures at 85.925 mm (3.382
in.) or less the oil pump assembly must be replaced.
(5) Measure the thickness of the inner rotor (Fig.
99). If the inner rotor thickness measures at 12.005
mm (0.472 in.) or less then the oil pump assembly
must be replaced.
(6) Slide outer rotor into the body of the oil pump.
Press the outer rotor to one side of the oil pump body
and measure clearance between the outer rotor and
the body (Fig. 100). If the measurement is 0.235mm
(0.009 in.) or more the oil pump assembly must be
replaced.
(7) Install the inner rotor in the into the oil pump
body. Measure the clearance between the inner and
outer rotors (Fig. 101). If the clearance between the
rotors is .150 mm (0.006 in.) or more the oil pump
assembly must be replaced.
(8) Place a straight edge across the body of the oil
pump (between the bolt holes), if a feeler gauge of
.095 mm (0.0038 in.) or greater can be inserted
between the straightedge and the rotors, the pump
must be replaced (Fig. 102).
NOTE: The 4.7 Oil pump is released as an assem-
bly. There are no DaimlerChrysler part numbers for
Sub-Assembly components. In the event the oil
pump is not functioning or out of specification it
must be replaced as an assembly.
Fig. 97 Checking Oil Pump Cover Flatness
1 - STRAIGHT EDGE
2 - FEELER GAUGE
3 - OIL PUMP COVER
9 - 134 ENGINE - 4.7LWJ

ASSEMBLY
(1) Wash all parts in a suitable solvent and inspect
carefully for damage or wear.
(2) Install inner and outer rotors
(3) Install oil pump cover plate and install cover
bolts and tighten them to 12 N´m (105 in. lbs.).
(4) Prime oil pump before installation by filling
rotor cavity with engine oil.
(5) If oil pressure is low and pump is within spec-
ifications, inspect for worn engine bearings or other
causes for oil pressure loss.
INSTALLATION
(1) Position the oil pump onto the crankshaft and
install two oil pump retaining bolts.
(2) Position the primary timing chain tensioner
and install the two retaining bolts.
(3) Tighten the oil pump and primary timing chain
tensioner retaining bolts to 28 N´m (250 in. lbs.) in
the sequence shown (Fig. 103).
(4) Install the secondary timing chain tensioners
and timing chains (Refer to 9 - ENGINE/VALVETIMING/TIMING BELT/CHAIN AND SPROCKETS -
INSTALLATION).
(5) Install the timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).
(6) Install the pick-up tube and oil pan (Refer to 9
- ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
Fig. 98 Measuring Outer Rotor Thickness
Fig. 99 Measuring Inner Rotor Thickness
Fig. 100 Measuring Outer Rotor Clearance in
1 - FEELER GAUGE
2 - OUTER ROTOR
Fig. 101 Measuring Clearance Between Rotors
1 - OUTER ROTOR
2 - FEELER GAUGE
3 - INNER ROTOR
WJENGINE - 4.7L 9 - 135
OIL PUMP (Continued)

INTAKE MANIFOLD
DESCRIPTION
The intake manifold is made of a composite mate-
rial and features long runners which maximizes low
end torque. The intake manifold uses single plane
sealing which consist of eight individual press in
place port gaskets to prevent leaks. Eight studs and
two bolts are used to fasten the intake to the head.
DIAGNOSIS AND TESTINGÐINTAKE
MANIFOLD LEAKAGE
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
(2) Spray a small stream of water at the suspected
leak area.
(3) If a change in RPM is observed the area of the
suspected leak has been found.
(4) Repair as required.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove air cleaner housing and throttle body
resonator (Fig. 104).
(3) Disconnect throttle and speed control cables.
(4) Disconnect electrical connectors for the follow-
ing components:
²Manifold Absolute Pressure (MAP) Sensor
²Intake Air Temperature (IAT) Sensor
²Throttle Position (TPS) Sensor
²Coolant Temperature (CTS) Sensor
²Idle Air Control (IAC) Motor
(5) Disconnect vapor purge hose, brake booster
hose, speed control servo hose, positive crankcase
ventilation (PCV) hose.
Fig. 102 Measuring Clearance Over Rotors
1 - STRAIGHT EDGE
2 - FEELER GAUGE
Fig. 103 Oil Pump and Primary Timing Chain
Tensioner Tightening Sequence
Fig. 104 Throttle Body Resonator
1 - THROTTLE BODY RESONATOR
2 - BOLT
3 - BOLT
9 - 136 ENGINE - 4.7LWJ
OIL PUMP (Continued)

INSPECTION
(1) Inspect the exhaust manifold for cracks in the
mating surface and at every mounting bolt hole.
(2) Using a straight edge and a feeler gauge, check
the mating surface for warp and twist.
(3) Inspect the manifold to exhaust pipe mating
surface for cracks, gouges, or other damage that
would prevent sealing.
INSTALLATION
(1) Install exhaust manifold and gasket from below
engine compartment.
(2) Install lower exhaust manifold fasteners. DO
NOT tighten until all fasteners are in place.
(3) Lower vehicle and install upper exhaust mani-
fold fasteners. Tighten all manifold bolts starting at
center and working outward to 25 N´m (18 ft. lbs.).
CAUTION: Over tightening heat shield fasteners,
may cause shield to distort and/or crack.
(4) Install exhaust manifold heat shield. Tighten
fasteners to 8 N´m (72 in. lbs.), then loosen 45
degrees.
(5) Install starter and fasteners.
(6) Connect exhaust pipe to manifold.
(7) Connect heater hoses at engine.
(8) Install fastener attaching A/C accumulator.
(9) Install A/C compressor and fasteners.
(10) Install accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(11) Install washer bottle and battery tray assem-
bly.
(12) Install PDC.
(13) Install battery and connect cables.
(14) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
VALVE TIMING
DESCRIPTION - TIMING DRIVE SYSTEM
The timing drive system has been designed to pro-
vide quiet performance and reliability to support a
non-free wheelingengine. Specifically the intake
valves are non-free wheeling and can be easily dam-
aged with forceful engine rotation if camshaft-to-
crankshaft timing is incorrect. The timing drive
system consists of a primary chain and two second-
ary timing chain drives (Fig. 109).
OPERATION - TIMING DRIVE SYSTEM
The primary timing chain is a single inverted tooth
type. The primary chain drives the large fifty tooth
idler sprocket directly from a 25 tooth crankshaftsprocket. Primary chain motion is controlled by a
pivoting leaf spring tensioner arm and a fixed guide.
The arm and the guide both use nylon plastic wear
faces for low friction and long wear. The primary
chain receives oil splash lubrication from the second-
ary chain drive and oil pump leakage. The idler
sprocket assembly connects the primary and second-
ary chain drives. The idler sprocket assembly con-
sists of two integral thirty tooth sprockets and a fifty
tooth sprocket that is splined to the assembly. The
spline joint is a non ± serviceable press fit anti rattle
type. A spiral ring is installed on the outboard side of
the fifty tooth sprocket to prevent spline disengage-
ment. The idler sprocket assembly spins on a station-
ary idler shaft. The idler shaft is press-fit into the
cylinder block. A large washer on the idler shaft bolt
and the rear flange of the idler shaft are used to con-
trol sprocket thrust movement. Pressurized oil is
routed through the center of the idler shaft to pro-
vide lubrication for the two bushings used in the
idler sprocket assembly.
There are two secondary drive chains, both are
inverted tooth type, one to drive the camshaft in each
SOHC cylinder head. There are no shaft speed
changes in the secondary chain drive system. Each
secondary chain drives a thirty tooth cam sprocket
directly from the thirty tooth sprocket on the idler
sprocket assembly. A fixed chain guide and a hydrau-
lic oil damped tensioner are used to maintain tension
in each secondary chain system. The hydraulic ten-
sioners for the secondary chain systems are fed pres-
surized oil from oil reservoir pockets in the block.
Each tensioner also has a mechanical ratchet system
that limits chain slack if the tensioner piston bleeds
down after engine shut down. The tensioner arms
and guides also utilize nylon wear faces for low fric-
tion and long wear. The secondary timing chains
receive lubrication from a small orifice in the ten-
sioners. This orifice is protected from clogging by a
fine mesh screen which is located on the back of the
hydraulic tensioners.
STANDARD PROCEDURE
STANDARD PROCEDURE - ENGINE TIMING -
VERIFICATION
CAUTION: The 4.7L is a non free-wheeling design
engine. Therefore, correct engine timing is critical.
NOTE: Components referred to as left hand or right
hand are as viewed from the drivers position inside
the vehicle.
WJENGINE - 4.7L 9 - 141
EXHAUST MANIFOLD - RIGHT (Continued)

TIMING BELT/CHAIN AND
SPROCKETS
REMOVAL
(1) Disconnect negative cable from battery.
(2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Remove right and left cylinder head covers
(Refer to 9 - ENGINE/CYLINDER HEAD/CYLIN-
DER HEAD COVER(S) - REMOVAL).
(4) Remove radiator fan (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - REMOVAL).
(5) Rotate engine until timing mark on crankshaft
damper aligns with TDC mark on timing chain cover
(Fig. 120) (#1 cylinder exhaust stroke) and the cam-
shaft sprocket ªV8º marks are at the 12 o'clock posi-
tion (Fig. 121).(6) Remove power steering pump.
(7) Remove access plugs (2) from left and right cyl-
inder heads for access to chain guide fasteners (Fig.
122).
(8) Remove the oil fill housing to gain access to the
right side tensioner arm fastener.
(9) Remove crankshaft damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL) and timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL).
(10) Collapse and pin primary chain tensioner
(Fig. 123).
CAUTION: Plate behind left secondary chain ten-
sioner could fall into oil pan. Therefore, cover pan
opening.
(11) Remove secondary chain tensioners.
(12) Remove camshaft position sensor from right
cylinder head (Fig. 124).
CAUTION: Care should be taken not to damage
camshaft target wheel. Do not hold target wheel
while loosening or tightening camshaft sprocket.
Do not place the target wheel near a magnetic
source of any kind. A damaged or magnetized tar-
get wheel could cause a vehicle no start condition.
CAUTION: Do not forcefully rotate the camshafts or
crankshaft independently of each other. Damaging
intake valve to piston contact will occur. Ensure
negative battery cable is disconnected to guard
against accidental starter engagement.
(13) Remove left and right camshaft sprocket bolts.
(14) While holding the left camshaft steel tube
with adjustable pliers, (Fig. 125) remove the left
camshaft sprocket. Slowly rotate the camshaft
approximately 15 degrees clockwise to a neutral posi-
tion.
(15) While holding the right camshaft steel tube
with adjustable pliers, (Fig. 126) remove the right
camshaft sprocket. Slowly rotate the camshaft
approximately 45 degrees counterclockwise to a neu-
tral position.
Fig. 120 Engine Top Dead Center (TDC) Indicator
Mark
1 - TIMING CHAIN COVER
2 - CRANKSHAFT TIMING MARKS
WJENGINE - 4.7L 9 - 147

body. Install Special Tool 8514 lock pin into hole on
front of tensioner. Slowly open vise to transfer piston
spring force to lock pin (Fig. 128).
(2) Position primary chain tensioner over oil pump
and insert bolts into lower two holes on tensioner
bracket. Tighten bolts to 28 N´m (250 in. lbs.).
CAUTION: Overtightening the tensioner arm torxT
bolt can cause severe damage to the cylinder head.
Tighten torxTbolt to specified torque only.
(3) Install right side chain tensioner arm. Apply
MopartLock N, Seal to torxtbolt, tighten bolt to 17
N´m (150 in. lbs.).
NOTE: The silver bolts retain the guides to the cyl-
inder heads and the black bolts retain the guides to
the engine block.(4) Install the left side chain guide. Tighten the
bolts to 28 N´m (250 in. lbs.).
CAUTION: Overtightening the tensioner arm torxT
bolt can cause severe damage to the cylinder head.
Tighten torxTbolt to specified torque only.
(5) Install left side chain tensioner arm. Apply
MopartLock N, Seal to torxtbolt, tighten bolt to 17
N´m (150 in. lbs.).
(6) Install the right side chain guide. Tighten the
bolts to 28 N´m (250 in. lbs.).
(7) Install both secondary chains onto the idler
sprocket. Align two plated links on the secondary
chains to be visible through the two lower openings
on the idler sprocket (4 o'clock and 8 o'clock). Once
the secondary timing chains are installed, position
special tool 8515 to hold chains in place for installa-
tion (Fig. 129).
Fig. 127 Timing Chain System
1 - RIGHT CAMSHAFT SPROCKET AND SECONDARY CHAIN
2 - SECONDARY TIMING CHAIN TENSIONER (LEFT AND RIGHT
SIDE NOT COMMON)
3 - SECONDARY TENSIONER ARM
4 - LEFT CAMSHAFT SPROCKET AND SECONDARY CHAIN
5 - CHAIN GUIDE
6 - TWO PLATED LINKS ON RIGHT CAMSHAFT CHAIN7 - PRIMARY CHAIN
8 - IDLER SPROCKET
9 - CRANKSHAFT SPROCKET
10 - PRIMARY CHAIN TENSIONER
11 - TWO PLATED LINKS ON LEFT CAMSHAFT CHAIN
12 - SECONDARY TENSIONER ARM
9 - 150 ENGINE - 4.7LWJ
TIMING BELT/CHAIN AND SPROCKETS (Continued)

(22) Install timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION) and crankshaft
damper (Refer to 9 - ENGINE/ENGINE BLOCK/VI-
BRATION DAMPER - INSTALLATION).
(23) Install cylinder head covers (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
NOTE: Before installing threaded plug in right cylin-
der head, the plug must be coated with sealant to
prevent leaks.
(24) Coat the large threaded access plug with
MopartThread Sealant with Teflon, then install
into the right cylinder head and tighten to 81 N´m
(60 ft. lbs.) (Fig. 122).
(25) Install the oil fill housing.
(26) Install access plug in left cylinder head (Fig.
122).
(27) Install power steering pump.
(28) Install radiator fan (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - INSTALLATION).
(29) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(30) Connect negative cable to battery.
Fig. 132 Tightening Right Side Camshaft Sprocket
Bolt
1 - TORQUE WRENCH
2 - SPECIAL TOOL 6958 WITH ADAPTER PINS 8346
3 - LEFT CAMSHAFT SPROCKET
4 - RIGHT CAMSHAFT SPROCKET
Fig. 133 Measuring Idler Gear End Play
1 - IDLER SPROCKET ASSEMBLY
2 - DIAL INDICATOR
WJENGINE - 4.7L 9 - 153
TIMING BELT/CHAIN AND SPROCKETS (Continued)

FUEL SYSTEM
TABLE OF CONTENTS
page page
FUEL DELIVERY..........................1FUEL INJECTION........................31
FUEL DELIVERY
TABLE OF CONTENTS
page page
FUEL DELIVERY
DESCRIPTION..........................2
OPERATION............................2
DIAGNOSIS AND TESTING
FUEL PRESSURE LEAK DOWN TEST......2
STANDARD PROCEDURE - FUEL SYSTEM
PRESSURE RELEASE...................4
SPECIFICATIONS
FUEL SYSTEM PRESSURE..............4
TORQUE - FUEL DELIVERY..............4
SPECIAL TOOLS
FUEL SYSTEM........................5
FUEL FILTER/PRESSURE REGULATOR
DESCRIPTION..........................5
OPERATION............................5
REMOVAL.............................6
INSTALLATION..........................6
FUEL LEVEL SENDING UNIT / SENSOR
DESCRIPTION..........................7
OPERATION............................7
DIAGNOSIS AND TESTING - FUEL LEVEL
SENDING UNIT........................7
REMOVAL.............................7
INSTALLATION..........................8
FUEL LINES
DESCRIPTION..........................8
FUEL PUMP
DESCRIPTION..........................8
OPERATION............................9
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - FUEL PUMP
CAPACITY TEST.......................9
DIAGNOSIS AND TESTING - FUEL PUMP
AMPERAGE TEST......................9FUEL PUMP PRESSURE TEST...........11
FUEL PUMP MODULE
DESCRIPTION.........................13
OPERATION...........................13
REMOVAL.............................13
INSTALLATION.........................14
FUEL RAIL
DESCRIPTION
DESCRIPTION - 4.7L...................15
DESCRIPTION - 4.0L...................15
OPERATION
OPERATION - 4.7L....................15
OPERATION - 4.0L....................15
REMOVAL
REMOVAL - 4.7L......................15
REMOVAL - 4.0L......................17
INSTALLATION
INSTALLATION - 4.7L..................18
INSTALLATION - 4.0L..................18
FUEL TANK
DESCRIPTION.........................19
OPERATION...........................19
REMOVAL.............................19
INSTALLATION.........................20
INLET FILTER
REMOVAL.............................27
INSTALLATION.........................27
QUICK CONNECT FITTING
DESCRIPTION.........................27
STANDARD PROCEDURE - QUICK-CONNECT
FITTINGS...........................27
WJFUEL SYSTEM 14 - 1