JEEP CHEROKEE 1988 Service Repair Manual
Manufacturer: JEEP, Model Year: 1988, Model line: CHEROKEE, Model: JEEP CHEROKEE 1988Pages: 1378, PDF Size: 19.9 MB
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* E XH AU ST 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
Exhaust Systems Motorist Assurance Program
Standards For Automotive Repair
All Makes and Models
INTRODUCTION TO MOTORIST ASSURANCE PROGRAM (MAP)
CONTENTS
Motorist Assurance Program (MAP)
OVERVIEW OF MOTORIST ASSURANCE PROGRAM
OVERVIEW OF SERVICE REQUIREMENTS AND SUGGESTIONS
Exhaust
CATALYTIC CONVERTERS
EXHAUST AND TAIL PIPES
EXHAUST CONNECTIONS
HANGERS
HEAT RISERS (MECHANICAL EFE DEVICES)
HEAT SHIELDS
MANIFOLDS (CAST AND TUBE TYPE)
MECHANICAL EFE DEVICES
MUFFLERS AND RESONATORS
INTRODUCTION TO MOTORIST ASSURANCE PROGRAM (MAP)
OVERVIEW OF MOTORIST ASSURANCE PROGRAM
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
are continually re-published. In addition to these, standards for
Drive Train and Transmissions have recently been promulgated.
Participating shops utilize these Uniform Inspection & Communication
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Standards as part of the inspection process and for communicating
their findings to their customers.
The Motorist Assurance Program continues to work
cooperatively and proactively with government agencies and consumer
groups toward solutions that both benefit the customer and are
mutually acceptable to both regulators and industry. We maintain the
belief that industry must retain control over how we conduct our
business, and we must be viewed as part of the solution and not part
of the problem. Meetings with state and other government officials
(and their representatives), concerned with auto repair and/or
consumer protection, are conducted. Feedback from these sessions is
brought back to the association, and the program adjusted as needed.
To assure auto repair customers recourse if they were not
satisfied with a repair transaction, the Motorist Assurance Program
offers mediation and arbitration through MAP/BBB-CARE and other non-
profit organizations. MAP conducted pilot programs in twelve states
before announcing the program nationally in October, 1998. During the
pilots, participating repair shops demonstrated their adherence to the
Pledge and Standards and agreed to follow the UICS in communicating
the results of their inspection to their customers. To put some
"teeth" in the program, an accreditation requirement for shops was
initiated. The requirements are stringent, and a self-policing method
has been incorporated which includes the "mystery shopping" of
outlets.
We welcome you to join us as we continue our outreach... with
your support, both the automotive repair industry and your customers
will reap the benefits. Please visit MAP at our Internet site www.
motorist.org or contact us at:
1444 I Street, NW Suite 700
Washington, DC 20005
Phone (202) 712-9042 Fax (202) 216-9646
January 1999
MAP UNIFORM INSPECTION GENERAL GUIDELINES
OVERVIEW OF SERVICE REQUIREMENTS AND SUGGESTIONS
It is MAP policy that all exhaust, brake, steering,
suspension, wheel alignment, drive-line, engine performance and
maintenance, and heating, ventilation and air conditioning, and
electrical services be offered and performed under the standards and
procedures specified in these sections.
Before any service is performed on a vehicle, an inspection
of the appropriate system must be performed. The results of this
inspection must be explained to the customer and documented on an
inspection form. The condition of the vehicle and its components will
indicate what services/part replacements may be "Required" or
"Suggested". In addition, suggestions may be made to satisfy the
requests expressed by the customer.
When a component is suggested or required to be repaired or
replaced, the decision to repair or replace must be made in the
customer's best interest, and at his or her choice given the options
available.
This section lists the various parts and conditions that
indicate a required or suggested service or part replacement.
Although this list is extensive, it is not fully inclusive. In
addition to this list, a technician may make a suggestion. However,
any suggestions must be based on substantial and informed experience,
or the vehicle manufacturer's recommended service interval and must be
documented.
Some conditions indicate that service or part replacement is
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required because the part in question is no longer providing the
function for which it is intended, does not meet a vehicle
manufacturer's design specification or is missing.
Example:
An exhaust pipe has corroded severely and has a hole in it
through which exhaust gases are leaking. Replacement of the
exhaust pipe in this case is required due to functional
failure.
Example:
A brake rotor has been worn to the point where it measures
less than the vehicle manufacturer's discard specifications.
Replacement of the rotor is required because it does not meet
design specifications.
Some conditions indicate that a service or part replacement
is suggested because the part is close to the end of its useful life
or addresses a customer's need, convenience or request. If a
customer's vehicle has one of these conditions, the procedure may be
only to suggest service.
Example:
An exhaust pipe is rusted, corroded or weak, but no leaks are
present. In this case, the exhaust pipe has not failed.
However, there is evidence that the pipe may need replacement
in the near future. Replacement of the pipe may be suggested
for the customer's convenience in avoiding a future problem.
Example:
The customer desires improved ride and/or handling,
but the vehicle's shocks or struts have not failed. In this
case, replacement may be suggested to satisfy the customer's
wishes. In this case, replacement of the shocks or struts may
not be sold as a requirement.
A customer, of course, has the choice of whether or not a
shop will service his or her vehicle. He or she may decide not to
follow some of your suggestions. When a repair is required, a MAP shop
must refuse partial service on that system if, in the judgment of the
service provider, proceeding with the work could create or continue an
unsafe condition. When a procedure states that required or suggested
repair or replacement is recommended, the customer must be informed of
the generally acceptable repair/replacement options whether or not
performed by the shop.
When presenting suggested repairs to the customer, you must
present the facts, allowing the customer to draw their own conclusions
and make an informed decision about how to proceed.
The following reasons may be used for required and suggested
services. These codes are shown in the "Code" column of the MAP
Uniform Inspection & Communications Standards that follow:
Reasons to Require Repair or Replacement
A - Part no longer performs intended purpose
B - Part does not meet a design specification (regardless of
performance)
C - Part is missing
NOTE: When a repair is required, the shop must refuse partial
service to the system in question, if the repair creates
or continues an unsafe condition.
Reasons to Suggest Repair or Replacement
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1 - Part is close to the end of its useful life (just above
discard specifications, or weak; failure likely to occur
soon, etc.)
2 - To address a customer need, convenience, or request (to
stiffen ride, enhance performance, eliminate noise,
etc.)
3 - To comply with maintenance recommended by the vehicle's
Original Equipment Manufacturer (OEM)
4 - Technician's recommendation based on substantial and
informed experience
NOTE: Suggested services are always optional. When presenting
suggested repairs to the customer, you must present
the facts, allowing the customer to draw their own
conclusions and make an informed decision about how to
proceed.
EXHAUST
SERVICE PROCEDURES REQUIRED AND SUGGESTED FOR PROPER
VEHICLE OPERATION
WARNING: Federal EPA rules prohibit altering an exhaust system in
any way that defeats the emission reduction components of a
vehicle. Be sure to review and adhere to EPA policy on
removing and replacing catalytic converters. Where state or
local laws are stricter, they take precedence over these
guidelines.
NOTE: Some exhaust systems are of a welded design. It is not
required that the entire system be replaced. Determine the
need to replace individual components based on conditions of
component.
CATALYTIC CONVERTERS
CAUTION: Before working on an exhaust system, review EPA
regulations on removing and replacing catalytic converters.
NOTE: Any time a converter has failed, further diagnosis is
required to determine the reason(s) for converter failure.
CATALYTIC CONVERTER INSPECTION
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Condition Code Procedure
Air injection tube
broken ................. A ... Require repair or replacement
of injection tube or
replacement of catalytic
converter.
Air injection tube
burnt .................. A ... Require repair or replacement
of injection tube or
replacement of catalytic
converter.
Air injection tube
leaking ................ A ... Require repair or replacement
of injection tube or
replacement of catalytic
converter.
Air injection tube
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loose .................. A ... Require repair or replacement
of injection tube or
replacement of catalytic
converter.
Air injection tube
restricted ............. A ... Require repair or replacement
of injection tube or
replacement of catalytic
converter.
Air injection tube
threads damaged ........ A ... Require repair or replacement
of injection tube or
replacement of catalytic
converter.
Air injection tube
threads stripped
(threads missing) ...... A ... Require repair or replacement
of injection tube or
replacement of catalytic
converter.
Body cracked ............ B .. Require repair or replacement.
Converter empty ......... A .. Require repair or replacement.
Converter fill plug
missing ................ C .. Require repair or replacement.
Converter missing ....... C ............ Require replacement.
Exhaust gases leaking ... A .. Require repair or replacement.
Flanges leaking ......... A ... Require repair or replacement
of flanges.
Inlet pipes cracked ..... B .. Require repair or replacement.
Internal rattle (except
pellet-type) ........... 2 .......... (1) Further inspection
required.
Mounting brackets that
are part of converter
broken ................. A .. Require repair or replacement.
Obvious overheating ..... .. ......... ( 2) Require testing of
converter.
Outlet pipes cracked .... B .. Require repair or replacement.
Pieces of catalyst
material found
downstream ............. 1 ............ Suggest replacement.
Plugged ................. A ........ ( 3) Require replacement.
Testing has determined
that existing converter
has been lead-poisoned,
contaminated, or failed
testing ................ A .. Require repair or replacement.
( 1) - If the converter is breaking up, suggest converter
replacement. If an object has fallen into the converter,
remove the object.
( 2) - Overheating is caused by something other than the
converter. Further diagnosis is required to determine
the cause of the overheating.
( 3) - Determine cause and correct to ensure that new converter
will not become plugged.
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EXHAUST AND TAIL PIPES
NOTE: For pipes with resonators, also see MUFFLERS AND RESONATORS.
EXHAUST AND TAIL PIPE INSPECTION
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Condition Code](/img/16/57037/w960_57037-765.png "JEEP CHEROKEE 1988 Service Repair Manual \
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Condition Code")
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Condition Code Procedure
Bracket broken .......... A .. Require repair or replacement.
Pipe bent out of
position ............... B .. Require repair or replacement.
Pipe broken ............. A .. Require repair or replacement.
Pipe cracked ............ B .. Require repair or replacement.
Pipe leaking ............ A ............ Require replacement.
Pipe missing ............ C ............ Require replacement.
Pipe plugged ............ A ............ Require replacement.
Pipe weak due to
corrosion, but no leaks
present ................ 1 ............ Suggest replacement.
Weld broken ............. A .. Require repair or replacement.
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EXHAUST CONNECTIONS
EXHAUST CONNECTION INSPECTION \
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Condition Code Procedure
Attaching hardware
incorrect .............. B ......... Require replacement of
hardware.
Clamp broken ............ A ........... Require replacement.
Clamp loose ............. A . Require repair or replacement.
Clamp missing ........... C ........... Require replacement.
Corroded, affecting
structural integrity ... 1 ........... Suggest replacement.
Incorrect type (i.e.
flange, ball & socket
etc.) .................. B ........... Require replacement.
Leaking ................. A ................ Require repair.
Loose ................... A ................ Require repair.
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HANGERS
HANGER INSPECTION \
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Condition Code Procedure
Broken .................. A ............ Require replacement.
Corroded, affecting
structural integrity ... 1 ............ Suggest replacement.
Incorrect type .......... B ............ Require replacement.
Loose ................... A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
Out of position ......... B .. Require repair or replacement.
Rubber deteriorated ..... 1 ............ Suggest replacement.
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HEAT RISERS (MECHANICAL EFE DEVICES)
HEAT RISER (MECHANICAL EFE DEVICE) INSPECTION \
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Condition Code Procedure
Broken .................. A .......... Require replacement of
affected parts.
Diaphragm inoperative ... A ........ ( 1) Require replacement.
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Leaking ................. A .. Require repair or replacement.
Noisy ................... 2 ... Suggest repair or replacement
of affected parts.
Seized .................. A ... Require repair or replacement
of affected parts.
Spring broken ........... B .......... Require replacement of
spring(s).
Spring inoperative ...... A .......... Require replacement of
spring(s).
(1) - If the inoperative diaphragm is separate from the heat
riser, then require replacement of the inoperative
diaphragm. If the inoperative diaphragm is part of the
heat riser, then replace the heat riser.
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HEAT SHIELDS
HEAT SHIELD INSPECTION \
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Condition Code Procedure
Bent .................... B .. Require repair or replacement.
Broken .................. A ............ Require replacement.
Corroded, affecting
structural integrity ... 1 ............ Suggest replacement.
Loose ................... A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
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MANIFOLDS (CAST AND TUBE TYPE)
MANIFOLD (CAST AND TUBE TYPE) INSPECTION \
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Condition Code Procedure
Air injection tube in
manifold broken ........ A ... Require repair or replacement
of injection tube or
replacement of manifold.
Air injection tube in
manifold corroded,
affecting structural
integrity .............. 1 ......... Suggest replacement of
injection tube or manifold.
Air injection tube in
manifold leaking ....... A ... Require repair or replacement
of injection tube or
replacement of manifold.
Air injection tube in
manifold loose ......... A ................. Require repair.
Air injection tube in
manifold restricted .... A .......... Require replacement of
injection tube or manifold.
Air injection tube in
manifold threads
damaged ................ A ..... Require repair of injection
tube or manifold.
Air injection tube in
manifold threads stripped
(threads missing) ...... A .......... Require replacement of
injection tube or manifold.
Bolt broken ............. A ... Require replacement of bolts.
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Bolt loose .............. A ........... Require tightening or
replacement of bolts.
Bolt missing ............ C ... Require replacement of bolts.
Corroded, affecting
sealability ............ A .. Require repair or replacement.
Cylinder head threads
stripped ............... A ... Require repair or replacement
of cylinder head.
Gasket leaking .......... A ........... Require tightening or
replacement of gasket.
Heat stove bent ......... B ........... (1) Require repair or
replacement of stove.
Heat stove broken ....... A ......... ( 1) Require replacement
of stove.
Heat stove corroded,
affecting structural
integrity .............. 1 ......... ( 1) Suggest replacement
of stove.
Heat stove missing ...... C ......... ( 1) Require replacement
of stove.
Manifold broken ......... A .. Require repair or replacement.
Manifold cracked ........ B .. Require repair or replacement.
Manifold warped ......... A .. Require repair or replacement.
Out of specification .... B .. Require repair or replacement.
Stud broken ............. A .... Require replacement of stud.
Stud missing ............ C .... Require replacement of stud.
Stud threads damaged .... A ... Require repair or replacement
of stud.
Stud threads stripped
(threads missing) ...... A .... Require replacement of stud.
( 1) - Stove may not be available separately; this may require
replacement of manifold.
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MECHANICAL EFE DEVICES
See HEAT RISERS (MECHANICAL EFE DEVICES) .
MUFFLERS AND RESONATORS
MUFFLER AND RESONATOR INSPECTION \
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Condition Code Procedure
Body shell distorted,
affecting performance or
structural integrity ... A ............ Require replacement.
Corrosion hole .......... A ............ Require replacement.
Missing ................. C ............ Require replacement.
Mounting bracket broken . A .. Require repair or replacement.
Mounting bracket
cracked ................ B .. Require repair or replacement.
Nipple cracked .......... A .. Require repair or replacement.
Nipple loose ............ B ............ Require replacement.
Outer wrap peeling
(exhaust not leaking) .. 1 ............ Suggest replacement.
Plugged ................. A ............ Require replacement.
Puncture (other than a
drain hole) ............ A ............ Require replacement.
Rattling or knocking noise
from inside muffler .... B ............ Require replacement.
Seam open (exhaust
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leaking) ............... A ............ Require replacement.
Sound quality
unsatisfactory ......... 2 .. Suggest replacement to address
customer need and/or request.
Split (exhaust leaking) . A ............ Require replacement.
Weak due to corrosion, but
no leaks present ....... 1 ............ Suggest replacement.
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FU EL E VA PO RATIO N S YSTE M
1988 J e ep C hero ke e
1988 Exhaust Emission Systems
FUEL EVAPORATION SYSTEMS
JEEP
DESCRIPTION
The Evaporative Emission Control System (EECS), prevents raw
fuel vapors from entering the atmosphere. It consists of a venting
system which allows only vaporous fuel to be drawn into the system.
During engine operation, vapors are drawn through system
vent lines and into intake manifold. When engine is off, fuel vapors
are stored in vapor storage canister charcoal. Vapors are drawn into
intake manifold when engine is running again. See Fig. 1.
Fig. 1: Open-Bottom Canister (2-Tube Type)
Courtesy of General Motors Corp.
OPERATION