1993 Jeep Cherokee
1993 ENGINE PERFORMANCE
Chrysler Corp. Removal, Overhaul & Installation
Jeep; Cherokee, Grand Cherokee, Grand Wagoneer, Wrangler
INTRODUCTION
Removal, overhaul and installation procedures are covered in this article. If component removal and installation is primarily an unbolt and bolt-on procedure, only a torque specification may be furnished.
IGNITION SYSTEM
DISTRIBUTOR
CAUTION: Base ignition timing is not adjustable on any 2.5L, 4.0L or 5.2L engine. Base ignition timing and timing advance are controlled by the PCM. Since a conventional timing light can not be used to adjust distributor after installation, ensure distributor is returned to its original position.
Removal (2.5L & 4.0L)
Disconnect negative battery cable. Remove distributor cap.
Rotate engine crankshaft until distributor rotor is pointing toward
cylinder No. 1 of distributor cap and engine is at TDC.
Scribe mark on distributor and adjacent component as
reference to indicate rotor and distributor housing position when
reinstalling distributor. Disconnect camshaft position sensor harness
connector. Remove distributor hold-down nut. Lift distributor from
engine.
Installation (2.5L & 4.0L)
1) Position distributor in engine. Ensure "O" ring is
properly seated on distributor. Replace "O" ring if cracked or nicked. Carefully engage distributor driven gear with camshaft drive gear so when distributor is installed properly, rotor aligns with reference mark.
2) Install distributor cap. Check all high tension wires for
good connections. Install hold-down nut. Connect camshaft position
sensor wiring harness connector.
Removal (5.2L)
Disconnect negative battery cable. Remove distributor cap.
Rotate engine crankshaft until distributor rotor is pointing toward
cylinder No. 1 of distributor cap and engine is at TDC.
Scribe mark on distributor and adjacent component as
reference to indicate rotor and distributor housing position when
reinstalling distributor. Disconnect camshaft position sensor harness
connector. Remove distributor hold-down nut. Lift distributor from
engine.
Installation (5.2L)
NOTE: If engine has been rotated since distibutor removal, return engine to TDC.
1) Clean mounting surface. Oil "O" ring on distributor housing. Position distributor in engine. Ensure "O" ring is properly
seated on distributor. Replace "O" ring if cracked or nicked. Carefully engage distributor driven gear with camshaft drive gear so when distributor is installed properly, rotor aligns with reference mark.
2) Install hold-down clamp and bolt but do not tighten.
Rotate distributor housing until rotor is aligned with CYL. NO. 1 mark on camshaft position sensor. Tighten hold-down bolt to 200 INCH Lbs. (22.5 N.m).
3) Install distributor cap. Check all high tension wires for
good connections. Connect camshaft position sensor wiring harness
connector.
CAMSHAFT POSITION SENSOR
Removal & Installation (2.5L & 4.0L)
Remove distributor. See DISTRIBUTOR. Remove rotor. Scribe mark on distributor driven gear and distributor shaft for reassembly reference. Using pin punch, drive out distributor roll pin. Lightly tap on end of distributor shaft until gear and thrust washer are removed. Remove distributor shaft from housing. Unbolt and remove camshaft position sensor. To install, reverse removal procedure.
Removal & Installation (5.2L)
Disconnect negative battery cable. Remove distributor cap. Disconnect camshaft position sensor connector from harness connector. Remove distributor rotor. Lift and remove sensor from distributor. To install, reverse removal procedure.
CRANKSHAFT POSITION SENSOR
Removal (2.5 & 4.0L)
Disconnect sensor connector from main harness connector. Connector is located near rear of intake manifold. Raise and support vehicle. Remove sensor mounting bolts. Remove sensor. Sensor is mounted on transmission bellhousing.
Installation (2.5 & 4.0L)
To install, reverse removal procedure. Use only proper mounting bolt. Any other replacement bolt will cause improper sensor alignment. On Wrangler with 4.0L engine and automatic transmission, ensure paper self-adhesive spacer on end of sensor is replaced if old sensor is being reused. Paper spacer is used to set proper depth. Once engine is started, paper spacer wears away.
Removal (5.2L)
Remove spark plug cable loom and spark plug wires from
mounting stud on rear of right valve cover. Remove right exhaust
manifold heat shield. Disconnect hoses from EGR valve. Disconnect
connector and hoses at EGR transducer.
Remove EGR valve. Disconnect connector at Oil Pressure
Sending (OPS) unit. Using appropriate socket, remove OPS unit. Remove
EGR tube. Disconnect crankshaft connector from harness connector.
Remove crankshaft position sensor.
Installation (5.2L)
To install, reverse removal procedure. Replace all EGR valve and tube gaskets. Coat OPS unit threads with sealant before installing.
FUEL SYSTEM
FUEL SYSTEM PRESSURE RELEASE
WARNING: ALWAYS relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components.
Disconnect negative battery cable. Loosen fuel filler cap
to release tank pressure. Remove protective cap from pressure test
port on fuel rail. Using appropriate fuel pressure gauge/hose with
gauge removed, place gauge end of hose into approved gasoline
container.
To release pressure, screw other end of hose onto pressure
test port. After pressure is released, remove hose from test port and
install protective cap.
FUEL RAILS & INJECTORS
Removal & Installation (2.5L & 4.0L)
1) Relieve fuel system pressure. See
FUEL SYSTEM PRESSURE RELEASE. Remove and tag injector wiring harness connectors from each injector. Disconnect vacuum hose from fuel pressure regulator.
Disconnect fuel supply and fuel return lines. Remove fuel
rail mounting bolts. On automatic transmission vehicles, it may be
necessary to remove throttle line pressure cable and bracket.
Gently rock fuel rail until all injectors clear intake
manifold. Remove injector retaining clips and remove injectors. To
install, reverse removal procedure. Ensure fuel injectors are properly
seated in intake manifold.
CAUTION: The left and right fuel rails are replaced as an assembly. DO NOT attempt to separate rail halves at connecting hoses. DO NOT attempt to install a clamping device of any kind to hose(s). When removing fuel rail assembly, be careful not to bend or kink connecting hoses.
Removal (5.2L)
1) Release fuel system pressure. See
FUEL SYSTEM PRESSURE RELEASE. Disconnect negative battery cable. Remove air duct at throttle body. Remove throttle body from intake manifold. See THROTTLE BODY. Remove air conditioning compressor-to-intake manifold support bracket (if equipped).
Disconnect fuel injector wiring connectors (injector
connectors are numerically tagged for installation reference). Remove
vacuum line from fuel pressure regulator. Remove EVAP canister purge
solenoid/bracket assembly from intake manifold.
Disconnect 2 rear fuel rail fuel lines, and remove
remaining fuel rail mounting bolts. Gently rock and pull on left fuel rail and then right fuel rail until injectors start to clear intake manifold. Repeat procedure until injectors clear intake manifold, and remove fuel rail with injectors attached. Remove injector-to-fuel rail clips.
Installation (5.2L)
Lubricate injector "O" rings with a drop of clean engine
oil. Install injectors and clips into fuel rail receiver cups. Ensure
injectors and clips are fully seated. Position fuel rail/injector
assembly on intake manifold openings. Using care not to tear "O"
rings, guide each injector into intake manifold. Push right and then
left fuel rail down until injectors are bottomed on injector shoulder.
To complete installation, reverse removal procedure.
Connect negative battery cable, and check for leaks.
FUEL PUMP
NOTE: Fuel tank removal is not necessary when removing fuel pump module on Cherokee and Grand Cherokee.
Removal & Installation (Cherokee)
1) Relieve fuel system pressure. See
FUEL SYSTEM PRESSURE RELEASE. Remove fuel tank filler cap. Drain fuel tank until fuel level is below 1/4 full. Raise and support vehicle. Disconnect fuel gauge sending unit connector.
2) Disconnect fuel tank vent hose and return hoses from fuel
pump/fuel gauge sending unit. Using drift punch and hammer, carefully
remove fuel pump lock ring counterclockwise. Remove fuel pump/fuel
gauge sending unit and "O" ring. To install, reverse removal
procedure.
Removal & Installation (Grand Cherokee)
Drain and remove fuel tank. See FUEL TANK. Fuel pump module lock nut is threaded onto fuel tank. Remove fuel pump module lock nut. Remove pump. To install, reverse removal procedure. Ensure new gasket is installed.
Removal & Installation (Wrangler)
Disconnect negative battery cable. Remove fuel tank. See FUEL TANK. Remove mounting bolts and fuel pump module. To install, reverse removal procedure. Start engine and check for leaks.
FUEL TANK
Removal (Cherokee)
Disconnect negative battery cable. Remove fuel tank filler
cap. Using an approved fuel storage container, drain fuel tank. Raise
and support vehicle. Disconnect fuel fill hose and fill vent hose from
filler neck. Disconnect fuel pump module wire connector.
Disconnect fuel tank vent hose. Disconnect fuel supply and
return hoses from tank. Remove skid plate (if equipped). Remove fuel
tank shield. Support fuel tank with transmission jack. Remove support
straps. Lower and remove fuel tank.
Installation (Cherokee)
To install, reverse removal procedure. Start engine and check for leaks.
Removal & Installation (Grand Cherokee)
Disconnect negative battery cable. Release fuel system
pressure. See FUEL SYSTEM PRESSURE RELEASE. Raise and support vehicle.
Remove fuel tank filler and vent hose at filler tube. Remove rear tow
hooks (if equipped). Remove skid plate.
Remove trailer hitch (if equipped). Remove exhaust
tailpipe heat shield. Disconnect fuel supply line at filter.
Disconnect fuel return and vent lines at tank. Disconnect fuel pump
module harness connector. Support fuel tank with transmission jack.
Remove tank strap nuts and move straps away from tank.
Lower right side of tank while feeding fuel hoses through access hole
in body. Remove filler hoses from tank. Insert siphon hose and drain
tank. Lower and remove tank. To install, reverse removal procedure.
Removal & Installation (Wrangler)
Disconnect negative battery cable. Relieve fuel system
pressure. See FUEL SYSTEM PRESSURE RELEASE. Remove fuel tank filler
cap, and siphon fuel out of fuel tank. Raise and support vehicle.
Remove filler neck shroud. Disconnect filler vent hose and fuel filler
hose from tank.
Disconnect fuel gauge sending unit connector. Remove tie
straps securing connector harness to fuel supply and return tubes. Disconnect fuel tank vent hose from vent tube.
3) Remove fuel tank shield and skid plate as single assembly. Support fuel tank with floor jack, and remove support strap nuts. Lower fuel tank and remove. To install, reverse removal procedure.
THROTTLE BODY
Removal & Installation (2.5L & 4.0L)
Disconnect negative battery cable. Remove air cleaner
snorkel from throttle body. Disconnect idle air control motor and
throttle position sensor connectors.
Disconnect accelerator cable, throttle cable (A/T), and
speed (cruise) control cable (if equipped). Remove mounting bolts,
throttle body, and gasket. To install, reverse removal procedure.
Removal (5.2L)
Remove air duct. Release fuel system pressure. See
FUEL SYSTEM PRESSURE RELEASE. Disconnect negative battery cable.
Disconnect vacuum hoses and electrical connectors from throttle body.
Remove throttle cable, speed control cable and
transmission cable (A/T). Remove throttle return spring. Remove fuel intake and return hoses. Remove throttle body mounting screws, and lift throttle body from vehicle. Remove throttle body gasket from intake manifold.
Installation (5.2L)
Using a new gasket, install throttle body and tighten
mounting screws. Install fuel intake and return hoses using new
original-equipment type clamps.
Install throttle return spring. Install throttle cable.
Install speed control and transmission kickdown cables (if equipped).
Install wiring connectors and vacuum hoses. Install air cleaner.
Reconnect negative battery cable.
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS TABLE
Application Ft. Lbs. (N.m)
Coolant Temperature Sensor (2.5L & 4.0L) 21 (28)
Crankshaft Position Sensor (2.5L & 4.0L) 15 (19)
Distributor Hold-Down Bolt 17 (23)
Fuel Rail Bolt 20 (27)
Manifold Air Temperature Sensor 20 (27)
Oxygen (O2) Sensor 23 (31)
INCH Lbs. (N.m)
Coolant Temperature Sensor (5.2L) 60 (7)
Crankshaft Position Sensor (5.2L) 70 (8)
Fuel Filter Strap Bolt 108 (12)
Throttle Body Bolt 108 (12)
Throttle Position Sensor Bolt 60 (7)
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