1988 JEEP CHEROKEE air filter

1) Drain cooling system. Remove fan shroud and drive belts.
Remove fan assembly.
2) Disconnect heater hoses and lower radiator hose at water
pump. Remove water pump retaining bolts. Remove water pump.
Installation
Clean all gasket surfaces. Install water pump. Tighten bolts
to specification. Ensure pump turns freely. Reverse removal
procedures. Fill and purge air from cooling system.
NOTE: It may be necessary to remove heater hose to remove trapped
air if system cannot be purged using following procedures.
Cooling System Air Purge (Vehicles With Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Install
coolant caps. Operate engine to normal operating temperature. Shut off
engine and allow system to cool. Add coolant to recovery bottle.
Repeat procedure to obtain correct coolant level.
Cooling System Air Purge (Vehicles Without Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Operate
engine to normal operating temperature with radiator cap removed. Add
necessary coolant and install radiator cap.
NOTE: For further information on cooling system capacities and
other cooling system components, see ENGINE COOLING SYSTEMS
article.
ENGINE OILING
CRANKCASE CAPACITY
Crankcase capacity is 4 qts. (3.8 L) with oil filter change.
NORMAL OIL PRESSURE
Normal oil pressure should be 13 psi (.91 kg/cm) at 600 RPM
or 37-75 psi (2.6-5.3 kg/cm) at 1600 RPM.
OIL PRESSURE REGULATOR VALVE
Oil pressure regulator valve is located in oil pump body and
is nonadjustable.
OILING SYSTEM
Engine lubrication is provided by the distributor driven
gear-type oil pump. Oil is supplied through the full-flow oil filter
and into an internal oil passage. Internal passage runs along right
side of block and intersects lifter bores.
Oil is then routed to camshaft and crankshaft bearings. Oil
is supplied to rocker arms from the hydraulic lifters and through the
push rods. By-pass valves are located in oil filter mounting and oil
pump.
OIL PUMP
Removal
Remove oil pan. See OIL PAN REMOVAL article. Remove oil pump

Removal
Drain cooling system. Disconnect radiator and heater hoses
from pump. Remove drive belt(s). Remove fan shroud. Remove fan
assembly. Remove electric cooling fan (if equipped). Remove power
steering bracket from water pump. Remove water pump and gasket.
Installation
Ensure gasket surfaces are clean. Install water pump. Tighten
bolts to specification. Ensure pump turns freely. Reverse removal
procedures. Fill and purge air from cooling system.
NOTE: It may be necessary to remove heater hose to remove trapped
air if system cannot be purged using following procedures.
Cooling System Air Purge (Vehicles W/Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Install
coolant caps. Operate engine to normal operating temperature. Shut off
engine and allow system to cool. Add coolant to recovery bottle.
Repeat procedure to obtain correct coolant level.
Cooling System Air Purge (Vehicles W/O Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Operate
engine to normal operating temperature with radiator cap removed. Add
necessary coolant and install radiator cap.
NOTE: For further information on cooling systems, see appropriate
article in the ENGINE COOLING section.
LUBRICATION
CRANKCASE CAPACITY
Crankcase capacity for 4.0L is 5 1/2 qts. (5.2L) or 5 qts.
(4.7L) for 4.2L with oil filter change.
NORMAL OIL PRESSURE
Normal oil pressure should be 37-75 psi (2.6-5.3 kg/cm)
maximum above 1600 RPM. Minimum oil pressure should be 13 psi (.9
kg/cm
) at 600 RPM.
OIL PRESSURE REGULATOR VALVE
Oil pressure regulator valve is located in pump body. Valve
is nonadjustable and serviced as an assembly.
ENGINE OILING SYSTEM
Engine lubrication is provided by the distributor driven
gear-type oil pump. Oil is supplied through the full-flow oil filter
and into an internal oil passage. Internal passage provides oil to the
lifter bores. Oil is then routed to camshaft and crankshaft bearings.
Oil is supplied to rocker arms from the hydraulic lifters and through
the push rods.
OIL PUMP
Removal
Remove oil pan. See OIL PAN REMOVAL in this section. Remove

proper increased enrichment for the next engine start. Idle speed is
nonadjustable.
EMISSION CONTROL
The ECU electrically controls Exhaust Gas Recirculation (EGR).\
An ECU-controlled solenoid valve is used to control EGR valve
function. This valve is located on the left inner fender panel and is
operated by the ECU in response to coolant temperature, throttle
position, and manifold pressure.
Under conditions of engine warm-up, engine idle, wide open
throttle, or rapid acceleration/deceleration, the solenoid valve is
energized, blocking vacuum to the EGR valve. At normal operating
temperatures with engine speed above idle, the solenoid valve is de-
energized, allowing normal EGR valve function.
NOTE: If the electrical connector is removed from the EGR solenoid,
EGR flow will be allowed at all times.
A/C CLUTCH CONTROL
The ECU controls the A/C compressor clutch to improve idle
quality. The A/C compressor clutch will be engaged or disengaged as
deemed necessary by the ECU through the A/C clutch relay.
SHIFT LIGHT CONTROL
The shift light system is used on all manual transmission
equipped vehicles. The ECU monitors coolant temperature, throttle
position, vehicle speed, and engine speed to control the shift light.
The ECU calculates what gear position the vehicle should be in and
uses this information to turn on the light. The light indicates the
best shift point to the driver for maximum fuel economy.
The light is tested when the ignition switch is turned on.
When the engine is started, the light should go out. A transmission-
mounted switch prevents the light from illuminating when the
transmission is shifted into high gear. The ECU turns the light off if
the shift to the next higher gear is not performed within 3-5 seconds
after light comes on.
DIAGNOSIS & TESTING
PRELIMINARY CHECKS
Before assuming that the ECU is faulty, the following systems
and components must be in good condition and operating properly:
* Air filter.
* All support systems and wiring.
* Battery connections and specific gravity.
* Compression pressure.
* Electrical and vacuum connections to components, sensors and
switches.
* Emission control devices.
* Ignition system.
* All vacuum and fuel line (hose) connections.
FUEL SYSTEM TEST
Fuel Pressure
1) Remove cap from pressure test port on fuel rail and

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* A /C -H EA TE R S YSTE M U NIF O RM IN SPEC TIO N G UID ELIN ES *

1 988 J e ep C hero ke e
GENERAL INFORMATION
A/C-Heater System Motorist Assurance Program
Standards For Automotive Repair
All Makes and Models
INTRODUCTION TO MOTORIST ASSURANCE PROGRAM (MAP)
CONTENTS
Motorist Assurance Program (MAP)
OVERVIEW
OVERVIEW OF SERVICE REQUIREMENTS & SUGGESTIONS
Heating, Ventilation and Air Conditioning
ACCUMULATORS
ACTUATORS (ELECTRICAL)
ACTUATORS (VACUUM)
AIR CONDITIONING FITTINGS
AIR CONDITIONING HOSES
AIR CONDITIONING METAL LINES, HOSES AND FITTING ASSEMBLIES
AIR CONTROL DOORS
AIR DAMS (EXTERNAL)
AIR DISTRIBUTION SYSTEM
BELTS
BLEND DOORS
BLOWER FANS (BLOWER WHEEL OR SQUIRREL CAGE)
BLOWER MOTORS
BLOWER RESISTORS
BLOWER SWITCHES
CABIN AIR FILTERS
CIRCUIT BREAKERS
COMPRESSOR CLUTCH ASSEMBLIES
COMPRESSORS
CONDENSER AIR SEALS
CONDENSER FAN MOTORS
CONDENSERS
CONNECTORS
CONTROL CABLES
CONTROL HEADS (FUNCTION SELECTORS)
CONTROL LINKAGES
CONTROL MODULES
COOLANT
COOLING FAN BLADES
COOLING FAN CLUTCHES
COOLING FAN MOTORS
EVAPORATOR DRAIN TUBES
EVAPORATOR PRESSURE REGULATORS (EPRS)
EVAPORATORS
EXPANSION VALVES
FUNCTION SELECTORS
FUSES, FUSIBLE LINKS AND CIRCUIT BREAKERS
FUSIBLE LINKS
GASKETS
HEATER CASES
HEATER CONTROL VALVES
HEATER CORES

HEATER HOSES
HIGH PRESSURE RELIEF VALVES (HPRV)
IDLERS
IN-LINE FILTERS
METAL FITTINGS
METAL LINES
MIX AND AIR CONTROL DOORS (BLEND DOORS)
O-RINGS
ORIFICE TUBES
PILOT-OPERATED ABSOLUTES (POAS)
PLENUMS
PRESSURE CONTROL VALVES
PRESSURE SENSORS
PULLEYS
RADIATORS
RECEIVER-DRIERS
REFRIGERANT
REFRIGERANT OIL
RELAYS
SEALS
SERVICE PORTS
SPRING LOCK COUPLINGS
SUCTION THROTTLING VALVES (STVS)
SWITCHES (ELECTRICAL)
TENSIONERS
THERMISTORS AND PRESSURE SENSORS
THERMOSTATS AND HOUSINGS
VACUUM HOSES AND TUBES
VACUUM RESERVOIRS
VACUUM TUBES
VALVES IN RECEIVER (VIRS)
WATER PUMPS (ELECTRIC AUXILIARY)
WIRING HARNESSES AND CONNECTORS
MOTORIST ASSURANCE PROGRAM (MAP)
OVERVIEW
The Motorist Assurance Program is the consumer outreach
effort of the Automotive Maintenance and Repair Association, Inc.
(AMRA). Participation in the Motorist Assurance Program is drawn from
retailers, suppliers, independent repair facilities, vehicle
manufacturers and industry associations.
Our organization's mission is to strengthen the relationship
between the consumer and the auto repair industry. We produce
materials that give motorists the information and encouragement to
take greater responsibility for their vehicles-through proper,
manufacturer-recommended, maintenance. We encourage participating
service and repair shops (including franchisees and dealers) to adopt
(1) a Pledge of Assurance to their Customers and (2) the Motorist
Assurance Program Standards of Service. All participating service
providers have agreed to subscribe to this Pledge and to adhere to the
promulgated Standards of Service demonstrating to their customers that
they are serious about customer satisfaction.
These Standards of Service require that an inspection of the
vehicle's (problem) system be made and the results communicated to the\
customer according to industry standards. Given that the industry did
not have such standards, the Motorist Assurance Program successfully
promulgated industry inspection communication standards in 1994-95 for
the following systems: Exhaust, Brakes, ABS, Steering and Suspension,
Engine Maintenance and Performance, HVAC, and Electrical Systems.
Further, revisions to all of these inspection communication standards

Connector missing ....... C ............ Require replacement.
Inoperative ............. A ........ (2) Require replacement.
Insulation overheated ... A ............ Require replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
( 1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Inoperative includes intermittent operation or out of
OEM specification.









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BLOWER SWITCHES
See SWITCHES.
CABIN AIR FILTERS
CABIN AIR FILTER INSPECTION








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Condition Code Procedure
Air flow obstruction .... A ............. Require cleaning or
replacement.
Maintenance intervals ... 3 ............ Suggest replacement.
Missing ................. C ............ Require replacement.









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CIRCUIT BREAKERS
See FUSES, FUSIBLE LINKS AND CIRCUIT BREAKERS .
COMPRESSOR CLUTCH ASSEMBLIES
COMPRESSOR CLUTCH ASSEMBLY INSPECTION








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Condition Code Procedure
Air gap incorrect ....... B .. Require repair or replacement.
Bearing seized .......... A .. Require replacement of bearing
or assembly.
Bearing worn, affecting
performance ............ A .. Require replacement of bearing
or assembly.
Coil shows signs of
overheating ............ 1 .... Suggest replacement of coil.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted,

(such as compression
fitting) ............... B ............ Require replacement.
Flange leaking .......... A .. Require repair or replacement.
Leaking ................. A .. Require repair or replacement.
Restricted internally ... A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.









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EXPANSION VALVES
EXPANSION VALVE INSPECTION








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Condition Code Procedure
Application incorrect ... B ............ Require replacement.
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Corroded internally ..... 1 ............ Suggest replacement.
Filter screen torn ...... A .. Require replacement of screen.
Inoperative ............. A ........... ( 1) Require repair or
replacement.
Leaking ................. A ............ Require replacement.
Restricted .............. A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
( 1) - Expansion valve operation may be affected by capillary
tube location, corrosion, and insulation tape.
Inoperative includes intermittent operation.









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FUNCTION SELECTORS
See CONTROL HEADS (FUNCTION SELECTORS) .
FUSES, FUSIBLE LINKS AND CIRCUIT BREAKERS
FUSE, FUSIBLE LINK AND CIRCUIT BREAKER INSPECTION








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Condition Code Procedure
Application incorrect ... B ............ Require replacement.
Blown ................... A ........ ( 1) Require replacement.
Corroded, affecting
performance ............ A .. Require repair or replacement.
Corroded, not affecting
performance ............ 2 .. Suggest repair or replacement.
Cracked, affecting
performance ............ A .. Require repair or replacement.
Cracked, not affecting
performance ............ 1 .. Suggest repair or replacement.
Inoperative ............. A ... ( 2) Require replacement.
Insulation damaged,

Melted .................. 1 .. Suggest repair or replacement.
Missing ................. C ............ Require replacement.
Outer covering damaged .. 1 ............ Suggest replacement.
Outer covering damaged to
the extent that the inner
fabric is visible ...... A ............ Require replacement.
Protective sleeves
damaged ................ 2 . Suggest replacement of sleeves.
Protective sleeves
missing ................ 2 . Suggest replacement of sleeves.
Restricted, affecting
performance ............ A .. Require repair or replacement.
Restricted, not affecting
performance ............ 2 .. Suggest repair or replacement.
Routed incorrectly ...... 2 ................. Suggest repair.
Safety clip missing ..... C ............ Require replacement.
Spongy .................. 1 .. Suggest repair or replacement.
Stripped ................ A ............ Require replacement.
Surface cracks (dry-
rotted) ................ 1 .. Suggest repair or replacement.
Swollen ................. B ............ Require replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
Type incorrect .......... 1 .. Suggest repair or replacement.









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HIGH PRESSURE RELIEF VALVES (HPRV)
HIGH PRESSURE RELIEF VALVE (HPRV) INSPECTION








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Condition Code Procedure
Inoperative ............. A ........... ( 1) Require repair or
replacement.
Leaking ................. A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
( 1) - Inoperative includes intermittent operation or out of
OEM specification.









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IDLERS
See TENSIONERS.
IN-LINE FILTERS
IN-LINE FILTER INSPECTION








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Condition Code Procedure
Connection leaking ...... B .. Require repair or replacement.
Leaking ................. A .. Require repair or replacement.
Restricted .............. A ............ Require replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.









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