
1988 
SER 
This manual  applies to the  1988  Pontiac Firebird Models. 
It contains  the latest  product information  available at the 
time  of  publication  approval. lnformation  pertaining to 
the operation  of the  vehicle  is contained  in the  Owner's 
Manual  which accompanies  each vehicle.  The right  is 
reserved  to make changes  at any  time  without  notice. 
Any  references  to brand  names  in this manual  is intended 
merely  as an  example  of the  types  of 
lubricant% tools, 
materials, etc, recommended  for use  in servicing  1988 
Pontiac  Models. In all  cases, an equivalent  may be used. 
PONTIAC DIVISION 
GENERAL 
MOTORS CORPORATION 
PONTIAC,  MICHIGAN 48053 
1987 General  Motors Corp. All Rights  Reserved. 
No  part  of  this publication  may be reproduced,  stored in any 
retrieval  system  or transmitted  in any  form  or by  any  means, 
including  but  not  limited  to electronic,  mechanical, 
photocopying,  recording or otherwise,  without the prior written 
permission  of General  Motors Corp. This  includes  all  text, 
illustrations, tables  and charts. 
S-881  OF  9-87 Printed in Canada 
TABLE  OF CONTENTS 
SECTION  NAME 
GENERAL  INFORMATION 
OA. General  lnformation 
OB.  Maintenance & Lubrication 
1 SECT. 
HEATING  AND AIR CONDITIONING 
1A. Heating  and Ventilation 
1  B.  Air  Conditioning 
1D1. R-4 AIC Com~ressor Overhaul 
FRAME  AND BUMPERS 
2B.  Bumpers 2C. Chassis  Sheet Metal 
STEERING,  SUSPENSION,  WHEELS 
AND  TIRES 
3.  Diagnosis 
3A.  Wheel  Alignment 
3B5. Steering Wheels and Columns 3B6. Steering  Linkage 3B7. Power Steering  Gear and Pump 
3C.  Front Suspension 
3D.  Rear Suspension 
3E.  Tires  and Wheels 
FINAL  DRIVE 
4A.  Propeller  Shaft 
4B.  Rear  Axle 
4B1. Bora-Warner Axle 
BRAKES 5. Brakes 5A3. Comoosite Master Cvlinder 5B1. Disc  r rake Caliper ~ssembly - 300013100  Series 5B6. Disc Brake  Caliper  Assembly - 3548 
Series 
5C3. Direct  Torque  Drum Brake Assembly 5D2. Power  Head Assembly - Tandem Diaohraam 5F. ~~ecifications and Special  Tools 
ENGINE 6. Engine  General lnformation 6A2. 2.8L 6A3. 5.OL & 5.7L 6B. Engine Cooling 
6C. En~ine Fuel 
6D. ~ngine Electrical 6D1. Battery 6D2. Cranking  System 6D3. Charging System 6D4. Ignition System 6D5. Engine Wiring 
6E.  Driveabilitv  and Emissions 
6E2. ~missions' 6E3. Emissions - PFI 
6F.  Engine  Exhaust 
TRANSMISSION 7A. Automatic  Transmission - General 
lnformation 
7A1. Automatic  Transmission - On-Car 
Service 
700R4. Automatic  Transmission  Hydraulic Diagnosis 
700R4. Automatic  Transmission Unit  Repair 
76. 5-Speed  Manual Transmission 
7C.  Clutch 
CHASSIS  ELECTRICAL 8A. Electrical  Diagnosis 
8B.  Lighting  and Horns 
8C.  Instrument 
Panel, Gages 
& Console 
8E.  Windshield  Wiper  &Washer System 
ACCESSORIES 9A. Radio Systems  and Antennas 9B. Cruise Control 9G. Miscellaneous  Accessories 
I BODY SERVICE  MANUAL  END 
OF 
MANUAL   

HEATING AND VENTILATION 1.4-1 3 
ON-VEHICLE SERVICE 
HEATER  ELECTRICAL WIRING 
The heater  wiring  diagrams are shown  in 
Electrical  Diagnosis,  Section 
8A, and should  be 
referred  to for  diagnosis  of electrical  problems  in the 
heater  system. 
HEATER  CONTROL ASSEMBLY  AND BLOWER 
SWITCH 
Remove  or Disconnect 
1. Negative battery  cable. 
2. 
Control/radio console  trim plate. 
3.  Three 
(3)  controller  retaining  screws  and pull 
controller  out  from console. 
4. Control cables and electrical  connections. 
5. Blower  switch from controller  if either  switch or 
controller  requires  replacement.  If controller  is 
being  replaced,  transfer blower  switch  to new 
controller. 
Install  or Connect 
1. When  installing  controller, install  lower  right 
screw first  to properly  align  controller in console. 
2.  Blower  switch to  controller. 
3. Control  cables and electrical  connections. 
4.  Three  (3) controller  retaining  screws  and 
controller  to console. 
5. Control/radio console  trim plate. 
6. Negative  battery cable. 
TEMPERATURE  CONTROL, POWER  VENT, 
HEATER  DEFROST  CABLE 
Remove or Disconnect 
1. Hush panel(s) (see  Section 8C): 
a. Temperature 
cable - R.H. hush panel. 
b. 
Heateddefrost cable - R.H. hush  panel. 
c.  Vent 
cable 
- L.H.  hush  panel. 
2. 
Control/radio console  trim plate. 
3.  Three  (3) controller  retaining  screws  and pull 
controller  out  from console. 
4. Control cable  requiring  replacement  at control 
end. 
5. Cable  at mode  control  end (temperature  cable: 
remove cable link  cover  at crank  location). 
Install  or Connect 
1. When  installing  controller, install  right  lower 
screw first  to align  control  in  console. 
2.  Cable 
at mode  control  end (temperature  cable: 
install  cable link  cover  at crank  location). 
3.  Control  cable at control  end. 
4. Three  (3) controller  retaining  screws  and 
contoller  in  console. 
5. Control/radio console  trim plate. 
6. Hush panel(s) (see Section 8C). 
7. Fully  cycle controls to  adjust cables  and check  for 
proper  operation. 
HEATER  CORE 
Remove  or Disconnect 
Battery  ground cable. 
Drain  cooling  system. 
Heater  inlet  and  outlet  hoses from  heater  core. 
Right  lower  hush  panel  (see  Section 
8C). 
ECM attaching  screw and move  aside. 
Right  lower  I.P. trim  panel  (see  Section 
8C). 
Lower right  I.P. carrier-to-cowl  screw. 
Four  (4) heater  case cover  screws.  Upper left  screw 
may  be reached with  a long socket extension through 
the  I.P.  openings exposed  by removal  of the  lower 
right  I.P. trim  panel.  Carefully  lift the  lower  right 
corner  of the  I.P.  to align  socket  extension. 
Heater  case  cover. 
Core  support plate  and baffle  screws. 
Heater  core, support plate  and baffle  from  case. 
Install or Connect 
1. Heater  core, support  plate and baffle  to case. 
2.  Core support 
plate and baffle  screws. 
3.  Heater  case cover. 
4. Four (4) heater  case cover screws. 
5. Lower  right  I.P. carrier-to-cowl  screw. 
6. Right  lower I.P. trim  panel (see Section 8C). 
7. ECM. 
8.  Right  lower hush panel  (see  Section 
8C). 
9. Heater  inlet  and  outlet  hoses to heater  core. 
10. Refill  cooling  system  and check  for leaks. 
11. Battery  ground  cable. 
VENT CONTROL  CABLE (RAM VENT) 
Remove  or Disconnect 1 
1. Hush panel(s) (see  Section 8C). R.H.  cable 
replacement  will require  removal  of both  L.H. 
and  R.H.  hush panels. 
2.  Two 
(2)  retaining  screws  and individual  vent 
control. 
3.  Unclip 
cable control  clamp  at  vent duct  and 
disengage formed  end  of cable  from door  lever. 
1 Install or Connect 
1. Cable  control  clamp  at  vent duct  and install 
formed  end  of cable on  door lever. 
2, Two  (2)  retaining  screws  and individual  vent 
control. 
3.  Hush 
panel@) (see  Section 8C). 
4. Cycle 
control  fully and check  for  proper 
operation. 
HEATER  CONTROL WIRING I 
Remove or Disconnect 
1. Negative battery  cable.   

1A-14 HEATING AND VENTILATION 
2. Control/radio console trim  plate  and  hush 
panels. 
3. Three (3) screws  holding  controller  in console 
and  pull  controller  out  far  enough to disconnect 
electrical  connectors. 
4. Blower motor and blower  resistor  electrical 
connections. 
5. Carefully  pull cowl  grommet from cowl and pull 
wiring  harness  through  cowl  hole  into engine 
compartment. 
Install  or Connect 
1. When  reinstalling  controller,  install  lower  right 
screw first  to align  controller. 
2. Cowl  grommet  on  cowl and wiring  harness. 
3. Blower  motor and blower  resistor  electrical 
connections. 
4. Three (3) screws  holding  controller in  console 
and  connect  electrical  connectors. 
5. Control/radio console trim plate  and  hush 
panels. 
6. Negative  battery cable. 
HEATER/VENTILATION/DEFROSTER DUCTS 
See  section 8C for  removal. 
LOWER  (FLOOR) HEATER  OUTLET 
Remove or Disconnect 
1. Console  (see  Section 8C). 
2. L.H. and R.H. hush panels.  (see  Section 8C). 
3. Two  (2) floor outlet retaining  screws. 
4. Floor  outlet from core  case. 
Install  or Connect 
1. Floor  outlet  to core  case. 
2. Two (2) floor outlet retaining  screws. 
3. L.H. and R.H. hush  panels. 
4. Console. 
BLOWER  MOTOR 
Remove or Disconnect 
1.  Negative  battery cable. 
2. Electrical  connections  at blower  motor  and 
blower  resistor. 
3. Blower  motor cooling  tube. 
4. Blower  motor retaining  screws and remove 
motor/cage assembly  from case. 
5. Holding  blower motor cage,  remove  cage 
retaining  screw and slide cage  from motor  shaft. 
Install  or Connect 
1. Blower  motor cage and retaining  screw. 
2.  Blower 
motor retaining  screws  and 
motor/cage 
assembly in case. 
3. Blower  motor cooling  tube. 
4. Electrical  connections  at blower  motor and 
blower  resistor. 
5. Negative  battery cable. 
6. Reinstall radio capacitor in proper  location, if so 
equipped.   

18-28 AIR CONDITIONING 
DO NOT REPLACE the accumulator assembly 
when: 
1.  Merely  a dent  is found  in the  outer  shell of the 
accumulator. 
2.  A 
vehicle  is involved  in a collision and  no phys- 
ical  perforation  to  the accumulator  is found. 
OM-VEHICLE SERVICE 
R-"1 CHARGING  CAPACITIES 
The 420ml (14 fl. oz.)  disposable  can of R-12 
refrigerant  is equivalent  to .399 kg (. 88 lb.). 
BLOWER MOTOR 
a Remove or Disconnect 
1.  Disconnect  negative  battery  cable. 
2.  Remove  motor cooling  tube. 
3.  Disconnect  electrical connections. 
4. Remove blower motor attaching  screws, remove 
motor  and case  assembly. 
5. Loosen  retaining  nut  and remove  blower  cage 
from  motor  shaft. 
6. Inspect  blower  cage for  broken  vanes,  etc. 
Replace  if necessary. 
Install  or Connect 
1.  Reverse  removal  procedure  to reinstall.  Replace 
seals  or  sealant as required. 
HI-BLOWER  RELAY 
Relay is a plug-in  type  with connector  mounted 
on  top  of the  evaporator case. 
BLOWER RESISTOR 
Remove  or Disconnect 
1. Disconnect  negative  battery  cable. 
2. Disconnect electrical connections. 
3.  Remove  two (2)  screws,  remove resistor. 
Install or Connect 
1.  Reverse  removal  procedure to  reinstall. 
CONTROLLER,  BLOWER SWITCH OR 
WCUUM VALVE 
Remove or Disconnect 
1.  Disconnect  negative  battery  cable. 
2. Remove NC control-radio console trim  plate. 
3. Remove three (3) NC control retaining  screws. 
4. Pull A/C control out and  disconnect  electrical 
and  vacuum  connections  and  remove  tempera- 
ture  cable. 
5. Remove A/C control and  replace  vacuum valve 
or  blower  switch  as required. 
Install  or Connect 
1. Reverse  removal  procedure  to  reinstall.  Install 
lower right screw  in controller first to align con- 
troller  in console. 
TEMPERATURE CONTROL CABLE, 
VACUUM  HARNESS 
Remove or Disconnect 
1. Remove  the  following  hush panel(s): 
a. Vacuum Harness - R.H.  and L.H.  hush 
panel. 
b.  Temperature  Cable 
- R.H. hush panels. 
Remove 
controller/radio console  trim plate. 
Remove  three  (3)  controller screws  and  pull 
controller  partially  out of console. 
Disconnect  controller 
end(s) of  temperature 
cable 
andlor vacuum  harness. 
Disconnect  component 
end(s) of  temperature 
cable 
andlor vacuum  harness. 
Install or Conned 
1.  Reverse  removal  procedure to reinstall.  When 
installing  controller,  install  lower  right  screw 
first  to align  controller  location.  Replace any 
retaining  straps, etc. removed. 
2. Perform  functional check  of controller. 
CONTROL WlRlNG HARNESS 
a Remove  or Disconnect 
1. Disconnect  negative  battery  cable. 
2.  Remove 
control/radio console  trim  plate  and 
hush  panels  (see  Section 
8C). 
3.  Remove  three (3) screws  holding control in con- 
sole  and pull  control out  far enough  to  discon- 
nect  electrical  and vacuum  connector. Remove 
controller. 
4. Remove  instrument  panel  carrier  (see  Section 
8C). 
5. Remove heater  case covers (core  and mode door 
sides). 
6. Remove  two (2)  interior  screws  and  one (1) 
exterior  nut holding  case  to  cowl. Pull left  side 
of  case  back  to  gain  access to  harness  at cowl. 
Case  will still  be retained  by one (I) screw 
behind  the  evaporator  core 
- do not attempt 
complete removal  of case. - 
7. Loosen  cowl grommet and disconnect  purple 
vacuum  line.   

IGNITION SYSTEM 6D4-1 
ON SYSTEM 
CONTENTS 
General Description ............................... 6D4-1 Service  Procedures ............................. 6D4-3 
Ignition System .......................................... 6D4-1 
Ignition  System .......................................... 6D4-3 
Distributor Ignition ................................ 6D4-1 
Distributor Ignition ................................ 6D4 -3 
Diannosis .................................................... 6D4-3 On-Car Service ......................................... 6D4-5 - 
Ignition System .......................................... (334-3 Ignition  System ........................... .. .............. 6D4-5 
Distributor ................................................. 6D4 -7 HE1 Distributor .................................... 6D4-3 
GENERAL DESCRIPION 
The engine electrical system includes  the battery, 
ignition  (primary  and secondary),  starter (and  related 
wiring)  and the generator  (and  related  wiring). 
Diagnostic  charts (see Section  6D) will aid  in 
trouble-shooting  system  faults. When a fault  is traced 
to  a  particular  component, refer to that  components' 
section  of the  service  manual. 
IGNITION SYSTEM 
Distributor  Ignition 
The  ignition  circuit  consists  of the  battery, 
distributor,  ignition  switch,  spark plugs and primary 
and  secondary  wiring. Refer  to the  Battery  portion  of 
this  section for  battery  information. 
PIE1 Distributor 
The Nigh Energy Ignition  (HEI) distributor with 
Electronic  Spark Timing (EST),  used on most engines, 
combines  all  ignition  components  in one  unit.  The 
ignition  coil is in  the  distributor  cap  and  connects 
through  a  resistance brush to the  rotor. 
The  distributor  has an internal  magnetic  pick-up 
assembly which  contains  a permanent  magnet,  a pole 
piece  with internal  teeth and  a  pick-up coil. When  the 
teeth  of the  timer  core,  rotating inside the pole  piece, 
line  up with  the teeth  of the  pole  piece,  an induced 
voltage  in the pick-up coil signals  the electronic module 
to  trigger the coil  primary circuit.  The primary current 
decreases  and a high  voltage  is induced  in  the  ignition 
coil  secondary  winding.  This voltage  is directed 
through the rotor and  secondary leads to fire  the spark 
plugs.  The capacitor  in the distributor  is for radio  noise 
suppression, 
All spark  timing  changes  in the 
HE1 (EST) 
distributor  are done  electronically  by an Electronic 
Control  Module  (ECM),  which monitors information 
from  various  engine  sensors,  computes the desired 
spark  timing  and signals  the distributor  to change  the 
timing  accordingly. 
A back-up  spark  advance  system 
is  incorporated  to signal  the ignition  module in case  of 
(ECM) failure.  No vacuum  or mechanical  advance  is 
used.  Further  (EST)  information  is found  in  sections  6E 
Emissions  Control, and 
8A Electrical 
Troubleshooting. 
Ignition  Timing 
Timing specifications  for each engine  are listed  in 
Section 
6E. When  using a timing  light,  connect  an 
adapter  between  the No.  1 spark  plug and  the  No. 1 
spark  plug wire,  or use  an inductive  type pick-up. 
Do 
not  pierce  the plug lead. 
Once  the insulation of  the 
spark  plug cable  has been  broken, voltage  will jump  to 
the  nearest  ground,  and  the  spark  plug will not fire 
properly. 
Always  follow the tune-up  label 
procedures  when adjusting timing. 
Some engines  will incorporate a  magnetic  timing 
probe  hole  for use  with  special  electronic  timing 
equipment.  Fig. 
1A shows  a typical  magnetic  probe 
hole.  Consult  manufacturer's  instructions  for use of 
this  equipment. 
Secondary  Wiring 
The spark  plug wiring  used with ignition systems 
is  a carbon  impregnated  cord conductor,  encased in an 
8MM (5/16") diameter  silicone  rubber jacket.  The 
silicone jacket  withstands very high  temperatures  and 
also  provides  an excellent  insulator  for the  higher 
voltage  of the 
HE1 system.  Silicone  spark plug  boots 
form  a  tight  seal  on  the plug. 
The  boot  should be 
twisted 1/2 turn before removing. Care should 
also  be exercised  when connecting  a timing  light  or 
other  pick-up  equipment.  Do not  force  anything 
between  the boot  and wiring,  or through  the silicone 
jacket.  Connections  should  be made  in  parallel  using 
an  adapter.  DO NOT  pull on  the wire  to remove.  Pull 
on  the  boot,  or use  a tool  designed  for this  purpose. 
Spark  Plugs 
Resistor  type,  tapered  seat  spark plugs are used 
on  all  engines  (except aluminum  heads). No gasket  is 
used  on  these  tapered  seat  plugs. See Figs. 
1B and 1C 
for an explanation  of coding  on  spark plugs. 
Normal  service is assumed  to be  a  mixture  of 
idling,  slow speed,  and high  speed  driving.  Occasional 
or  intermittent  high-speed driving  is needed  for  good   

684.4 IGNITION SYSTEM 
a spark  plug  wire  from  a spark plug,  twist  the 4. Do not  wipe  grease  from  module,  or distributor 
boot  on the  spark  plug  and  pull 
on the  boot to  base, 
if same module  is to  be  replaced. 
remove  the wire,  or use  a special tool designed  to 
remove  spark plug  boots. 
Install  or Connect 
Remove  or Disconnect 
1. Ignition  switch battery  feed wire  and tachometer 
lead  (if equipped)  from  distributor  cap. Also 
release  the coil  connectors  from  the cap.  (DO 
NOT  use a screwdriver  or tool  to release  the 
locking  tabs.) 
2. Distributor  cap  by turning  four screws 
counterclockwise.  Move  cap out of the  way. 
3. Four-terminal  ECM harness  from  distributor. 
4. If  necessary,  remove  secondary  wires from  cap, 
release wiring harness  latches and remove wiring 
harness  retainer.  The spark  plug  wire  numbers 
are  indicated  on the  retainer. 
5. Distributor  clamp screw and  hold-down  clamp. 
6. Note position  of rotor,  then pull distributor  up 
until  rotor  just stops  turning  counterclockwise 
and  again  note position  of rotor. 
To  insure correct  timing of the  distributor, 
the  distributor  must be INSTALLED  with 
the  rotor  correctly  positioned  as noted. 
If  the  engine  was accidentally  cranked  after  the 
distributor  was removed,  the following  procedure  can 
be  used  for  installing: 
1. Remove  No. 1 spark  plug. 
2. Place finger over No. 1 spark  plug hole  and crank 
engine  slowly until compression  is felt. 
3. Align  timing  mark  on pulley to "0" on engine 
timing  indicator. 
4. Turn rotor to point  between  No. 1 and No. 8 
spark  plug  towers  on distributor  cap  on V8 
engines, between No. 1 and No. 6 on V6 engines, 
and  No. 
1 and  No. 4 on 4 cylinder  engines. 
5. Install distributor  and connect ignition  feed wire. 
6. Install  distributor  cap and  spark  plug  wires. 
7. Check  engine timing  (see Set Ignition  Timing). 
Install or Connect 
1. Insert  distributor,  positioning rotor as  removed. 
2. Distributor  hold-down clamp and screw. 
3. Wiring  harness  retainer  and  secondary  wires, if 
removed. 
4. ECM  harness  connector. 
5. Distributor cap. 
6. Coil connectors. 
7. Battery  wire and  tachometer  lead, if equipped. 
Module 
It  is not  necessary  to remove  the distributor  from 
car. 
Remove  or Disconnect 
1. Distributor  cap  and rotor. 
2. Two  module  attaching screws, and lift module 
UP. 3. Leads  from module.  (Observe color code on  leads 
as these cannot  be interchanged.) 
NOTICE: If a new  module  is to  be  installed,  a 
package  of silicone grease  will be included with it. 
Spread  the grease  on the  metal  face of the  module 
and  on the  distributor  base where  the module 
seats.  This grease is necessary  for module cooling. 
1. Module. 
2. Module leads  (observe  color code). 
3. Attaching  screws to module. 
4. Rotor. 
5. Cap. 
Pick-Up  Coil 
1. Remove  distributor  from  car  and follow 
instructions  in Unit  Repair,  as  applicable. 
Rotor 
Fig. 1 
1. Remove distributor  cap. 
2. The rotor  is retained  by two  screws  and is 
provided  with  a slot which  fits over  a square  lug, 
, 
so that  the  rotor can  be  installed  in only  one 
position. 
Integral  Ignition Coil 
Fig. I 
Remove  or Disconnect 
1. Distributor  cap. 
2. Three coil  cover  attaching screws, and lift off 
cover. 
3. Coil  attaching  screws and lift  ignition  coil  and 
leads  from cap. 
Install  or Connect I 
1. Coil  and  attaching  screws. 
2. Coil  leads. 
3. Coil  cover and attaching  screws. 
Capacitor 
Fig. 1 
The capacitor  is part  of the  coil  wire  harness 
assembly.  Since  the capacitor  is used  only  for radio 
noise  suppression,  it  will seldom  need replacement. 
Remove  or Disconnect I 
1. Distributor  cap and  rotor. 
2. Capacitor  attaching screw and unplug connector 
from  module.  It may  help to loosen  the module. 
Install  or Connect I 
1. Plug into  module. 
2. Capacitor  and hold-down  screw (be sure  ground 
lead  is under  screw).   

IGNITION SYSTEM 6014.5 
3. Rotor and  cap. 4. Turn off the  engine  and remove  the timing  light. 
Reconnect  the number  one  spark plug wire,  if 
Set Ignition Timing removed. 
Spark Plug Wires 1. Refer  to the  tune-up  label located  in the  engine 
compartment.  Follow  all instructions  on the  Use 
care  when  removing  spark plug  wire  boots 
label.  from 
spark  plugs.  Twist the boot 
1/2 turn  before 
removing  and pull  on  the 
boot only to remove  the 
With  ignition  off, connect  the pick-up  lead  of 
timing  light  to the  number  one spark  plug.  Use 
a jumper  lead  between  the wire  and plug,  or an 
inductive type pick-up. 
DO NOT pierce  the wire, 
or  attempt  to insert  a wire between  the boot  and 
the  wire.  Connect  the timing  light  power  leads 
according  to manufacturer's  instructions. 
Start the  engine and aim the timing  light at the 
timing  mark. The line on the  balancer  or pulley 
will  line up  at  the  timing mark. If a  change  is 
necessary,  loosen  the  distributor hold-down 
clamp  bolt at  the  base of the  distributor.  While 
observing  the mark  with the timing light,  slighty 
rotate  the  distributor  until the line indicates  the 
correct  timing. Tighten  the hold-down  bolt  and 
re-check  the timing.  wire. 
When  replacing  plug  wires,  route the wires 
correctly  and through  the proper  retainers.  Failure to 
route  the wires  properly can  lead to radio  ignition noise 
and  crossfiring  of the  plugs,  or shorting  of the  leads  to 
ground. 
Special  care should  be exercised when reinstalling 
spark  plug  boots,  to assure  that the metal  terminal 
within  the boot  is  fully  seated  on the  spark  plug 
terminal  and  that the boot has not  moved on the  wire. 
If  boot  to wire  movement  has occurred,  the boot  will 
give  a false visual  impression  of being  fully  seated. 
A 
good  check  to assure  that boots  have been  properly 
assembled  is to  push  sideways  on the  installed  boots. 
If  they  have  been correctly  installed, a  stiff boot, with 
only slight looseness,  will be noted.  If the  terminal has 
not  been  properly  seated  on the  spark  plug,  only  the 
resistance  of the  rubber  boot will be felt  when pushing 
sideways. 
ON-CAR SERVICE 
I I -COI L & BRACKET  ASM.  2-DISTRIBUTOR  3-COIL WIRE I 
Fig. 601 Distributor and Coil - LB8   

6EZ-B-2 5.OL (VIN E) DRIVEABILITY AND EMISSIONS 
Problem may or may not  turn "ON"  the "Service  Engine Soon" light, or store a code. 
DO  NOT  use the trouble  code charts  in Section 
"A"  for intermittent  problems. The fault  must  be 
present  to locate  the  problem.  If a fault  is 
intermittent,  use of trouble  code charts  may result 
in  replacement  of good  parts. 
@ Most  intermittent  problems are caused  by faulty 
electrical  connections  or wiring.  Perform 
careful  check of suspect  circuits  for: 
- Poor mating  of the  connector  halves,  or 
terminals,  not fully seated in the  connector 
body  (backed  out). 
I - Improperly  formed  or damaged  terminals. 
All  connector  terminals  in problem  circuit 
should  be carefully  reformed  to increase 
contact  tension. 
- Poor terminal  to wire  connection.  This 
requires  removing  the terminal  from the 
connector  body to check  as outlined  in the 
Introduction  to Section 
"6E". 
@ If  a  visual  (physical)  check does not find  the 
cause  of the  problem,  the car  can  be driven  with 
a  voltmeter  connected  to a suspected  circuit or a 
"Scan"  tool may  be used.  An  abnormal  voltage 
reading,  when the problem occurs,  indicates the 
problem  may be in that  circuit.  If the  wiring 
and  connectors check  OK, and a trouble  code  was 
stored  for a circuit  having  a sensor,  except 
for  Codes  44 and  45, substitute  a known  good 
sensor  and recheck. 
@ Loss  of trouble  code memory.  To check, 
disconnect  TPS and idle  engine  until "Service 
Engine  Soon" light comes 
"ON". Code 22  should 
be  stored,  and kept  in memory, when ignition  is 
turned  "OFF" for at least  10 seconds.  If not,  the 
ECM 
is faulty. 
@ An  intermittent "SES" light,  and no trouble 
codes,  may be caused  by: 
- Electrical  system interference  caused  by a 
defective  relay, ECM driven  solenoid,  or switch. 
They  can cause  a sharp  electrical  surge. 
Normally,  the problem  will occur  when  the 
faulty  component  is operated. 
- Improper  installation  of electrical  options, such 
as  lights,  2-way radios,  etc. 
- EST wires  should  be routed  away from spark 
plug  wires,  ignition  system components,  and 
generator.  Wire  for CKT 453  from  ECM to 
ignition  system should be a good  ground. 
- Ignition  secondary  shorted to ground. 
- CKTs 419 ("SES" light)  or 451  (Diagnostic  Test) 
intermittently  shorted to ground. 
- ECM power  grounds. 
HARD START 
Definition: Engine  cranks OK, but  does not start  for a long 
time.  Does eventually  run, or may  start but immediately  dies. 
, < 
@ CHECK: 4. Connect  a radiator test pump  to the  line  and 
- For water  contaminated fuel. apply 103 kPa (15 psi)  pressure.  If the 
- Fuel  system pressure  CHART A-7. pressure will hold  for 60 seconds,  the check 
- TPS  for sticking  or binding  should read less  than 
valve is OK. 
1.25 volts on a  "Scan"  tool. @ Check ignition  system for: 
- No crank  signal; see CHART C-1B. - Proper  output with ST-125. 
- EGR  operation;  CHART C-7. - Worn shaft. 
- Fuel System - CHART A-7. - Rare and shorted wires. 
- For  a faulty  in-tank  fuel pump  check  valve, - Pickup  coil resistance  and connections. 
which  would allow the fuel  in the  lines to drain 
- Loose  ignition  coil connections. 
back  to  the tank  after  the engine  is stopped.  To 
- Moisture in distributor  cap. 
check  for this  condition: 
- Spark  plugs,  wet plugs,  cracks,  wear, 
1.  Ignition  "OFF". 
improper  gap, burned  electrodes,  or  heavy 
2. Disconnect fuel line at the  filter 
deposits. 
3. Remove the tank  filler  cap. @ If engine  starts but then,  immediately  stalls, 
open  distributor  bypass line. If engine  then 
starts,  and  runs  OK,  replace  distributor pickup 
coil. 
@ Check  CKT 423 (EST)  for short  to ground.