fuel pump PONTIAC FIERO 1988 Service Repair Manual

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

OB-4 MAINTENANCE AND LUBRICATION
Tire and wheel operation - Be alert to a vibra-
tion of the steering wheel or seat at normal highway
speeds. This may mean a wheel balance is needed. Also, a
pull right or left on a straight, level road may show the
need for
a tire pressure adjustment or wheel alignment.
Steering system operation - Be alert to
changes in steering action. An inspection is needed when
the steering wheel is harder to turn or has too much free
play or if unusual sounds are noted when turning or
parking.
Headlight aim operation - Take note of light
pattern occasionally. If beam aim doesn't look right,
headlights should be adjusted.
AT EACH FUEL FILL
Engine oil level check - Check engine oil level
and add if necessary. See your Owner's
Manual for further
details.
NOTICE: A large loss in this system may indicate a
problem. Have it inspected and repaired at once.
Engine coolant level and condition - Check
engine coolant level in coolant reservoir tank and add if
necessary. Replace if dirty or rusty. See your Owner's
Manual for further details.
NOTICE: A large loss in this system may indicate a
problem. Have it inspected and repaired at once.
Windshield washer fluid level check -- Check
washer fluid level in container and add if necessary.
Hood latch operation - When opening hood on
cars equipped with hoods that open from the front, note
the operation of secondary latch. It should keep hood from
opening all the way when primary latch is released. Make
sure that hood closes firmly.
AT LEAST MONTI-ILY
Tire and wheel inspection and pressure
check--
Check tires for abnormal wear or damage. Also,
check for damaged wheels. Keep pressures as shown on
Tire Placard on the driver's door (include spare unless it is
a stowaway). Pressure should b\: checked when tires are
"cold". See "Tires" in Owner's Manual for further
infomation.
Light operation check - Check operation of
license plate light, side-marker lights, headlights includ-
ing high beams, parking lights, taillights, brake lights.
turn signals, backup lights, instrument panel and interior
lights and hazard warning flashers.
Fluid leak check - After the car has been parked
for a while, inspect the surface beneath the car for water,
oil, fuel or other fluids. Water dripping from the air
conditioning system after use is normal. If you notice fuel
leaks or fumes, the cause should be found and corrected at
once.
AT LEAST TWICE A YEAR (FOR EXAMPLE,
EVERY SPRING AND FALL)
Power steering pump fluid level check --
Check power steering pump fluid level in accordance with
Owner's Manual instructions and keep at proper level.
NOTICE: A large loss in this system may indicate a
problem. Have it inspected and repaired at once.
Brake master cylinder reservoir fluid level
check ---- Check fluid and keep at proper level. Note: It is
normal for the brake fluid level to go down slightly as the
brake pads wear
- so be sure to keep reservoir filled.
NOTICE: A large loss in this system may indicate a
problem. Have
it inspected and repaired at once.
Clutch system service --- manual transmis-
sionltransaxle --- For cars equipped with hydraulic
clutch system, check the reservoir fluid level and add fluid
as required. All others, check clutch pedal free travel and
adjust as necessary. See your Owner's Manual for further
details.
~
NOTICE: A large loss in this system may indicate a
problem. Have it inspected and repaired at once.
Weatherstrip Lubrication - Clean surface and
then apply a thin film of silicone grease with a clean cloth.
EACH TIME OIL IS CHANGED
Automatic and manual transmissionltrans-
axle fluid level check - Check transmission/transaxle
fluid level and add as required. (Corvette only) if equipped
with manual transmission
- check fluid in the overdrive
unit and add as required.
NOTICE: A large loss in this system may indicate a
problem. Have
it inspected and repaired at once.
Brake systems inspection - For convenience,
the following should be done when wheels are removed
for rotation: Inspect lines and hoses for proper hookup,
binding, leaks, cracks, chafing, etc. Inspect disc brake
pads for wear and rotors for surface condition. Also in-
spect drum brake linings for wear and cracks. Inspect
other brake parts, including drums, wheel cylinders, park-
ing brake, etc. at the same time. Check parking brake
adjustment.
INSPECT BRAKES MORE OFTEN IF DRIVING
HABITS OR CONDITIONS RESULT IN FREQUENT
BRAKING.
Steering, suspension and front drive axle
boot and seal inspection
- Inspect front and rear
suspension and steering system for damaged, loose or
missing parts, signs of wear or lack of lubrication. Inspect
power steering lines and hoses for proper hookup, bind-
ing, leaks, cracks, chafing, etc. (On cars equipped with
manual steering gear, check for seal leakage.) On
front-
wheel-drive cars, clean then inspect drive axle boot seals
for damage, tears or leakage. Replace seals if necessary.
Exhaust system inspection - Inspect complete
system. Inspect body near the exhaust system. Look for
broken, damaged, missing or out-of-position parts as well
as open seams, holes, loose connections or other condi-
tions which could cause a heat buildup in the tloor pan or
could let exhaust fumes seep into the trunk or passenger
compartment.

AIR CONDITIONING 1B-29
1. 1.5 N.m (13 LBS. IN.) 8. BRACKET
2. SWITCH
9. AJC COMPRESSOR RELAY
3. ACCUMULATOR 10. BRAKE BOOSTER
4. HARNESS 11.
FUEL PUMP RELAY
5. BLOWER RESISTOR 12. FAN RELAY
6. HI BLOWER RELAY 13. AJC CONTROL
RELAY
7. BLOWER RELAY 14. BULK HEAD
J10255-18-F
Figure 27 A/C Module and Cowl Wiring

ENGINE GENERAL INFORMATION 6-1
SECTION 6
NE GENERAL NFORMAT
Description ............................................................... 6 TBI ...................................... .. ...... 6E2 ................ Engine Mechanical Multi Port Fuel Injection (MPFI) 6E3 -
............................................... 2.8L V-6 ....................................................... 6A2 Exhaust Systems 6F
5.OL V-8 ......................................................... 6A3 ~~~~~~l ~~f~~~~ti~~ ..................................... 6-2
............................ Engine Cooling ...................................................... 6B Engine Performance Diagnosis 6-3 ............................. Engine Fuel 6C Engine Mechanical Diagnosis
6-3 ........................................................... ................................... Engine Knock Diagnosis 6-4
Engine Electrical ................................................... 6D Compression Test ...................................... ... 6-5
................... Driveability and Emission Controls ...................... 6E Oil Leak Detection .. ..................... 6-5
ALL NEW GENERAL MOTORS VEHICLES ARE CERTIFIED BY THE UNITED STATES
ENVIRONMENTAL PROTECTION AGENCY AS CONFORMING TO THE REQUIREMENTS OF
THE REGULATIONS FOR THE CONTROL OF AIR POLLUTION FROM NEW MOTOR VEHICLES.
THlS CERTIFICATION IS CONTINGENT ON CERTAIN ADJUSTMENTS BEING SET TO
FACTORY STANDARDS. IN MOST CASES, THESE ADJUSTMENT POINTS EITHER HAVE
BEEN PERMANENTLY SEALED AND/OR MADE INACCESSIBLE TO PREVENT
INDISCRIMINATE OR ROUTINE ADJUSTMENT IN THE FIELD. FOR
THlS REASON, THE
FACTORY PROCEDURE FOR TEMPORARILY REMOVING PLUGS, CAPS, ETC., FOR
PURPOSES OF SERVICING THE PRODUCT MUST BE STRICTLY FOLLOWED AND,
WHEREVER PRACTICABLE, RETURNED TO THE ORIGINAL INTENT OF THE DESIGN.
DESCRIPTION OF: SECTION 6
SECTION 6A - ENGINE MECHANICAL used for each carburetor. TBI units are described in
This section general contains information on the Section 6E.
mechanical parts of the engine, such as block,
crankshaft, pistons, valve train, and camshaft, that are
common to most engines. Overhaul procedures,
removal and replacement procedures, and
s~ecifications are also covered. Subsections furnish
detailed information on each specific engine. Service
SECTION 6D - ENG l N E ELECTRICAL
information is also given that relates to that engine's
use in each
Carline. Specific subsections are: Items
covered in this section are battery,
generator, starter, primary and secondary ignition,
6A2
- 2.8L V-6 Engine
engine wire harness, spark plugs and wires, and
6A3
- 5.OL V-8 Engine
ignition switch.
SECTION 6B - ENGINE COOLING
Engine cooling system components such as
radiator, water pump, thermostat, and cooling fan, are
covered in this section. Accessory drive belts are also
covered, along with cooling system capacities.
SECTION 6C - FUEL SYSTEM
This section contains information on all the parts
of the fuel system
except the carburetor, or Throttle
Body Injection unit (TBI) itself. Items covered are fuel
tank, fuel pump, and fuel lines. Specific subsections are
SECTION 6E - DRIVEABILITY AND EMISSIONS
This section covers emission control systems
general information, and diagnostic procedures which
will lead to repairing performance and driveability
related problems for gasoline engine equipped vehicles.
All emission components are covered, as well as all
removal and replacement procedures. Instructions on
use of special tools are also given. Specific sections are:
6E
- Driveability and Emissions
6E2
- Fuel Injection (TBI)

6-2 ENGINE GENERAL INFORMATION
6E3 - Fuel Injection (Ported) This section has information
on all exhaust
system parts, such as tailpipes, mufflers, and the
SECTION 6F - EXHAUST SYSTEM catalytic converter.
GENERAL INFORMAflION
CLEANLINESS AND CARE
An automobile engine is a combination of many
machined, honed, polished and lapped surfaces with
tolerances that are measured in the ten-thousandths of
an inch. When any internal engine parts are serviced,
care and cleanliness are important. A liberal coating of
engine oil should be applied to friction areas during
assembly, to protect and lubricate the surfaces on
initial operation. Throughout this section, it should be
understood that proper cleaning and protection of
machined surfaces and friction areas is part of the
repair procedure. This is considered standard shop
practice, even if not specifically stated. PREVENTING
DAMAGE AND IN
CONTRIBUTING TO RELIABLE ENGINE
PERFORMANCE.
When raising or supporting the engine for any
reason, do not use a jack under the oil pan. Due to the
small clearance between the oil pan and the oil pump
screen, jacking against the oil pan may cause it to be
bent against the pump screen resulting in a damaged
oil pick-up unit.
When working on the engine, remember that the
12-volt electrical system is capable of causing short
circuits. When performing any work where electrical terminals could possibly be grounded, the ground cable
of the battery should be disconnected at the battery.
Any time the carburetor or air cleaner is
train components are removed removed, the intake opening should be covered. This for service, they should be in order' will protect against entrance of foreign be installed in the same locations, and with the same material, which could follow the intake passage into mating surfaces, as when removed
the cylinder and cause extensive damage when the -
Battery cables should be disconnected before any engin; is started.
major work is performed on the engine. Failure to IN THE MECHANICAL PROCEDURES
disconnect cables may result in damage to wire harness DESCRIBED IN THIS SECTION, GENERALLY
or other electrical parts. NO
REFERENCES WILL BE MADE TO THE
REMOVAL OF OPTIONAL EQUIPMENT SUCH
ENGINE SERVICE AS POWER STEERING PUMP, AIR
CONDITIONING COMPRESSOR, ETC.
THE FOLLOWING INFORMATION ON SHOULD IT BECOME NECESSARY TO
ENGINE SERVICE SHOULD BE NOTED REMOVE ANY SUCH ITEM TO
PERFORM
CAREFULLY, AS IT IS IMPORTANT IN OTHER SERVICE, REFER TO THE
APPROPRIATE SECTION OF THIS SERVICE
MANUAL FOR SPECIFIC INFORMATION.
ENGINE PERFORMANCE DIAGNOSIS
INTRODUCTION interchangeably for so long, it was necessary to decide
on the most common usage and then define them. If the
Engine Performance procedures are definition is not understood, and the exact Symptom is
guides that will lead to the most probable causes of not used, the Diagnostic procedure will not work. engine performance complaints. They cover the
components of the fuel, ignition, and mechanical It
is important to keep two facts in mind:
systems that could cause a particular
complaint, and 1. The procedures are written to diagnose problems
then outline repairs in a logical sequence. on cars
that have
"run well at one time" and
that time and wear have created the condition.
It is important to determine if the
"Service ~~~i~~ soon- light is "ON,~' or has come for 2. All possible causes cannot be covered,
a short interval while driving. If the
"Service Engine particularly with regard to emission controls. If
Soon" light has come "ON," the Computer doing the work prescribed does not correct the
Command Control System or DECS should be complaint, then either the wrong Symptom was
checked for stored
"Trouble Codes" (See Diagnostic used, or a more detailed analysis will have to be
Circuit Check, Section 6E, for the engine you are made.
working on) which may indicate the cause for the All of the Symptoms can be caused by worn out
performance
complaint.Each Symptom is defined, and or defective parts such as Spark Plugs, Ignition
it is important that the correct one be selected, based Wiring, etc. If time and/or mileage indicate that
on the complaints reported or found. The definition of parts should be replaced, it is recommended that
each symptom is included with the symptom. it
be done.
The words used may not be what you are used to Refer to:
in all cases, but because these terms have been used
@ Section 6E - Driveability and Emissions

ENGINE GENERAL INFORMATION 6-3
B, Section 6E2 - Fuel Injection (TBI)
B, Section 6E3 - Fuel Injection (Ported)
ENGINE MECHANICAL DIAGNOSIS
The following diagnostic information covers common problems and possible causes. When
the proper diagnosis is made, the problem should be corrected by adjustment, repair or part
replacement as required. Refer to the appropriate section of the manual for these procedures.
EXCESSIVE OIL LOSS
B, External oil leaks. Tighten bolts and/or replace o Continuous high speed driving, and/or severe
gaskets and seals as necessary. usage
such as trailer hauling, will normally cause
decreased oil mileage.
e Improper reading of dipstick. Check oil with car PCV system malfunctioning. on a level surface and allow adequate drain-down Valve guides and/or valve stem seals worn, or time.
seals omitted. Ream guides and install oversize
service valves and/or new valve stem seals.
Improper Use S.A'E' Piston rings broken, worn, or not seateded. Allow viscosity for prevailing temperatures. See
adequate time for rings to seat. Replace broken
Owner's Manual for proper specifications.
or worn rings, as necessary.
Piston improperly installed or misfitted.
LOW OIL PRESSURE
Slow idle speed. Set idle speed to correct
specification, if not ECM controlled.
Incorrect, or malfunctioning, oil pressure switch.
Incorrect, or malfunctioning, oil pressure gage.
Replace with proper gage.
.*
Improper oil viscosity, or diluted oil. install oil of
proper viscosity for expected temperature, or
install new oil if diluted with moisture or
unburned fuel mixtures.
o Oil pump worn or dirty.
e Plugged oil filter.
e Oil pickup screen loose or plugged.
B, Hole in oil pickup tube.
e Excessive bearing clearance. Replace if necessary.
o Cracked, porous or plugged oil galleys. Repair or
replace block.
o Galley plugs missing or misinstalled. Install
plugs, or repair as necessary.
VALVE TRAIN NOISE
e Low oil pressure. Repair as necessary. (See o Broken valve spring.
preceding diagnosis for low oil pressure.)
o Sticking valves.
o Loose rocker arm attachments. Inspect and B, Lifters worn, dirty, or defective. Clean, inspect,
test and replace as necessary.
repair as necessary.
o Camshaft worn, or poor machining. Replace
o Worn rocker arm and/or pushrod. camshaft.
B, Worn valve guides.
ENGINE KNOCK DIAGNOSIS
KNOCKS COLD AND CONTINUES FOR TWO TO THREE MINUTES
INCREASES
WITH TORQUE
o Vacuum operated EFE engines may have valve o Excessive piston to bore clearance. Replace
knock. Replace EFE valve. piston.
e Flywheel contacting splash shield. Reposition
splash shield.
e Loose or broken balancer or drive pulleys.
Tighten, or replace as necessary. Cold engine piston knock usually
disappears when the cylinder is grounded
out. Cold engine piston knock which
disappears in 1.5 minutes should be
considered acceptable.

6-4 ENGINE GENERAL INFORMATION
Bent connecting rod.
HEAVY KNOCK H0"FVVI"F TORQUE APPLIED
Broken balancer, or pulley hub. Replace parts as e Exhaust system grounded. Reposition as
necessary. necessary.
Loose torque converter bolts. Flywheel
cracked.
e Excessive main bearing clearance. Replace as
Accessory belts too tight or nicked. Replace
necessary.
and/or tension to specs as necessary.
e Excessive rod bearing clearance. Replace as
necessary.
LIGHT KNOCK HOT
Detonation or spark knock. Check operation of e Loose torque converter bolts.
EST or ESC (See Section
6D or 6E). Check e Exhaust leak at manifold. Tighten bolts and/or
engine timing and fuel quality.
replace gasket.
8 Excessive rod bearing clearance. Replace
bearings as necessary.
KNOCKS ON INITIAL START-UP BUT ONLY LASTS A FEW SECONDS
Noisy mechanical fuel pump. Replace pump.
When the engine is stopped, some valves
will be open. Spring pressure against lifters
Improper oil viscosity. Install proper oil viscosity will
tend to bleed lifter down. Attempts to
for expected temperatures. See Owner's Manual. repair
should be made only if the problem
is consistent.
Hydraulic lifter bleed down. Clean, test and @ Excessive crankshaft end clearance. Replace
replace as necessary. crankshaft
thrust bearing.
@ Excessive front main bearing clearance. Replace
worn parts.
KNOCKS AT IDLE HOT
Loose or worn drive belts. Tension and/or @ Excessive piston pin clearance. Ream and install
replace as necessary. oversize pins. (VIN R and 2) or replace piston
A/C Compressor or generator bearing. Replace and
pin.
as necessary.
e Connecting rod alignment. Check and replace
rods as necessary.
Noisy mechanical fuel pump. Replace pump.
8 Insufficient piston to bore clearance. Hone bore
Valve train. Replace parts as necessary. and
fit new piston.
@ Loose crankshaft balancer. Torque and/or
Improper oil viscosity. Install proper viscosity oil
replace worn parts.
for expected temperature4 See Owner" e Piston pin offset to wrong side. Install correct
ENGINE OVERHEATS
Coolant system leak, oil cooler system leak, or
2. Belt slipping or damaged. Replace tensioner, or
coolant recovery system not operating. Check for belt, as required.
leaks and correct as required. Check coolant
3. Thermostat stuck closed. Check and replace if
recovery tank, hose and radiator cap.
required.
4. Electrical cooling fan operation. See the
ELECTRICAL TROUBLESHOOTING
MANUAL.
5. Head gasket leaking. Check and repair as
required.

2.8 LITER V-6 BA2-1
TER V-6 V N CODES RPO
CONTENTS
GENERAL DESCRIPTION ........................ 6A2- 1
ENGINE LUBRICATIONS ......................... 6A2- 1
ON-VEHICLE SERVICE ............................. 6A2-7
Powertrain Mounts .................................... 6A2-7
Rocker Arm Cover .................................... 6A2-8
Intake Manifold .......................................... 6A2-9
Exhaust Manifold ................................... 6A2-9
Rocker Arm and Push Rod ....................... 6A2- 10
Valve Mechanism
....................................... 6A2- 10
Valve Stem Oil Seal and/or Valve
Spring
.................... .. .. ... ................... 6A2- 10
Valve Lifters
............................................. 6A2- l l
Cylinder Head ............................................ 6A2- 12
Rocker Arm Studs
.................................... 6A2- 13
Valve Guides
........................................... 6A2- 13
Valve Seats
................................................ 6A2- 14
Valves
......................................................... 6A2- 14
Torsional Damper
..................................... 6A2- 14 Crankcase
Front Cover
.............................. 6A2- 15
Oil Seal (Front Cover)
........................... .... 6A2- 15
Timing Chain
& Sprocket .......................... 6A2- 15
Camshaft
................................................... 6A2- 16
Camshaft Bearings
................................... 6A2- 16
Oil Pan
........................................................ 6A2- 17
Oil Pump
.................................................. 6A2- 18
Connecting Rod Bearings .......................... 6A2- 18
Main Bearings
............................................ 6A2- 19
Oil Seal (Rear Main)
.................................. 6A2-2 1
Pistons, Rings & Connecting Rods ........... 6A2-2 1
Honing or Reboring Cylinders .................. 6A2-23
Fitting Pistons ............................................ 6A2-24
.............................................. Piston Rings 6A2-24
Engine Assembly ...................................... 6A2-25
.................................................. Crankshaft 6A2-25
........................................ Sprocket or Gear 6A2-26
..................................... SPECIFICATIONS 6A2-26
GENERAL DESCRIPTION
CYLINDER BLOCK
The cylinder block is made of alloy cast iron and
has 6 cylinders arranged in a "V" shape with 3
cylinders in each bank. The cylinder banks are set at
a
60" angle from each other.
The right bank cylinders are
1, 3, 5. Cylinders 2,
4, 6 are on the left bank.
Four main bearings support the crankshaft which
is retained by bearing caps that are machined with the
block for proper alignment and clearances.
CYLINDER HEAD
The cast alloy iron cylinder heads have individual
intake and exhaust ports for each cylinder. Valve
guides are integral, and rocker arms are retained on
individual threaded studs.
CRANKSHAFT AND BEARINGS
The crankshaft is cast nodular iron with deep
rolled fillets on all six crankpins and two center main
journals. Four steel backed aluminum bearings are
used, with
#3 bearing being the end-thrust bearing.
CAMSHAFT AND DRIVE
sprocket is also hardened sintered iron, and is pressed
onto the nose of the crankshaft.
A rubber snubber is
used to dampen chain motion.
PISTONS AND CONNECTING RODS
The pistons are cast aluminum with steel struts
using two compression rings and one coil control ring.
The piston pin is offset
1.5mm towards the major
thrust side. This allows a gradual change in thrust
pressure against the cylinder wall as the piston travels
its path. Pins are chromium steel and have a floating
fit in the pistons. They are retained in the connecting
rods by a press fit.
Connecting rods are made of forged steel. Full
pressure lubrication is directed to the connecting rods
by drilled oil passages from the adjacent main bearing
journal.
VALVE TRAIN
A very simple ball pivot-type train is used.
Motion is transmitted from the camshaft through the
hydraulic lifter and push rod to the rocker arm. The
rocker arm
~ivots on its ball and transmits the
camshaft
mot'ion to the valve. The rocker arm ball
locates on a stud, threaded into the head, and is
The camshaft is cast alloy iron with tapered 13. by a nut. The push rod is located by a guide
2mm wide lobes, offset from the lifters and tapered to plate held under the rocker arm stud, assuring that the
provide positive valve lifter rotation. The camshaft is arm Operates in the plane the
support& by four journals and includes a
distributor/oil pump drive gear, and fuel pump INTAKE MANIFOLD - - eccentric.
The intake manifold is a three piece cast
A
3/8" pitch chain drives the camshaft through
aluminum unit. It centrally supports a fuel rail with 6
a hardened sintered iron sprocket. The crankshaft
fuel injectors.

6A2-16 2.8 LITER V-6
Figure 6A2-19 Camshaft Timing
2. Align dowel in camshaft with dowel hole in
camshaft sprocket, then install sprocket on
camshaft.
3. Draw the camshaft sprocket onto camshaft using
the mounting bolts. Torque to specifications.
4. Lubricate timing chain with engine oil.
5. Install crankcase front cover as previously
outlined.
Figure 6A2-20 Measuring Camshaft Lobe Lift
CAMSHAFT
Measuring Lobe Lift Procedure is similar to that
used for checking valve timing. If improper valve
operation is indicated, measure the lift of each push rod
in consecutive order and record the readings.
1. Remove the valve mechanism, as previously
outlined.
2. Position
indicator with ball socket adapater (Tool
5-8520) on push rod. Make sure push rod is in the
lifter socket.
3. Rotate the crankshaft slowly in the direction of
rotation until the lifter is on the heel of the cam lobe.
At this point, the push rod is in its lowest
position.
4. Set the dial indicator on zero, then rotate the
crankshaft slowly, or attach an auxiliary starter
switch and "bump" the engine over, until the
push rod is in the fully raised position (Figure
6A2-20).
CAUTION: Whenever the engine is
cranked remotely at the starter, with
a special jumper cable or other means,
the distributor primary lead must be
disconnected from the coil to prevent
electrical shock.
5. Compare the total lift recorded from the dial
indicator with the specifications.
6. If camshaft readings for all lobes are within
specifications, remove dial indicator assembly.
7. Install and adjust valve mechanism, as previously
outlined.
Removal
1. Remove valve lifters as previously outlined.
2. Remove crankcase front cover as previously
outlined.
3. Remove fuel pump and push rod.
4. Remove timing chain and sprocket as previously
outlined.
5. Remove camshaft.
NOTICE: All camshaft journals are the same
diameter and care must be exercised in removing
camshaft to avoid damage to bearings.
Inspection
The camshaft bearing journals should be
measured with a micrometer for an out-of-round
condition. If the journals exceed
.025mm out-of-round,
the camshaft should be replaced.
Installation
Whenever a new camshaft is installed, coat
camshaft lobes with
GM E.O.S, or equivalent.
Whenever a new camshaft is installed, install new
oil, new filter and replacement of all valve lifters is
recommended to insure durability of the camshaft
lobes and lifter feet.
1. Lubricate camshaft journals with engine oil and
install camshaft.
2. Install timing chain, as previously outlined.
3. Install fuel pump push rod and fuel pump.
4. Install crankcase cover, as previously outlined.
5. Install
lifters, as previously outlined.
6. Complete build up of engine.
CAMSHAFT BEARINGS
Removal
Camshaft bearings can be replaced while engine
is disassembled for overhaul or without complete
disassembly of the engine. To replace bearings without
complete disassembly remove the camshaft and
crankshaft leaving cylinder heads attached and pistons
in place. Before removing crankshaft, tape threads of

2.8 LITER V-6 6A2-25
Fitting
1. Select rings comparable in size to the piston being
used.
2. Slip
the compression ring in the cylinder bore;
then press the ring down into the cylinder bore
about 6mm above ring travel. Be sure ring is
square with cylinder wall.
3. Measure the space or gap between the ends of the
ring with a feeler gage (Figure
6A2-33).
4. If
the gap between the ends of the ring is below
specifications, remove the ring and try another
for fit.
5. Fit each compression ring to the cylinder in
which it is going to be used.
6. If the pistons have not been cleaned and inspected
as previously outlined, do so.
7. Slip the outer surface of the top and second
compression ring into the respective piston ring
groove and roll the ring entirely around the
groove (Figure
6A2-34). If binding occurs at any
point, the cause should be determined. If there is
a ring groove, remove by dressing with a fine cut
file. If the binding is caused by a distorted ring,
check a new ring.
Installation
1. Install oil ring spacer in groove being sure ends
are butted and not overlapped.
2. Hold
spacer ends butted and install lower steel oil
ring rail.
3. Install upper
steel oil ring rail with gap staggered.
4. Flex
the oil ring assembly to make sure ring is
free. If binding occurs, the cause should be
detemined. If caused by ring groove, remove by
dressing groove with a fine cut file. If binding is
caused by a distorted ring, check a new ring.
5. Install second compression ring. Stagger gap
from other rings.
6. Install top compression ring with gap properly
located.
ENGINE ASSEMBLY
Removal
Disconnect battery.
Remove air cleaner.
Remove hood. Drain radiator.
Remove lower radiator hose.
Remove upper fan shroud.
Remove upper radiator hose and coolant
recovery hose.
Remove transmission cooler lines. Remove radiator.
Remove fan assembly.
Remove heater hoses.
Disconnect carburetor linkage, includes cruise
control detent cable.
Remove vacuum brake booster line.
Remove distributor cap and lay wiring aside.
Disconnect necessary wires and hoses.
Remove power steering pump and lay aside. Raise
vehicle.
Remove exhaust pipes at exhaust manifold.
Remove dust cover.
Remove converter bolts.
Disconnect starter wires.
Remove bell housing bolts.
Remove motor mount through bolts.
Disconnect fuel lines at fuel pump.
Lower vehicle. Support transmission.
Remove
A.I.R./Converter pipes bracket.
Remove engine, include removing wire from
bracket at rear left of engine.
Installation
Position engine assembly in vehicle.
Attach motor mount to engine brackets and
lower engine in place.
Remove engine lifting device.
Remove transmission floor jack.
Raise vehicle on hoist.
Install mount "through" bolts. Torque to
specifications.
Install bell housing bolts. Torque to
specifications.
On vehicles with automatic transmission, install
converter to flywheel attaching bolts. Torque to
specifications.
Install flywheel splash shield of conveter housing
cover as applicable. Torque attaching bolts to
specifications.
Install starter wires.
Connect fuel lines.
Connect exhaust pipe at manifold.
Lower vehicle on hoist.
Reinstall power steering pump, if so equipped.
Connect necessary wires and hoses.
Install radiator and fan shroud and reconnect
radiator and heater hoses.
Fill cooling system.
Fill crankcase with oil. See owner's manual for
specifications.
Install air cleaner.
Install hood.
Connect battery cables.
NOTICE: To avoid possible arcing of battery,
connect positive battery cable first.
22. Start engine, check for leaks and check timing.
CRANKSHAFT
The crankshaft can be removed while the engine
is dissasembled for overhaul, as previously outlined or
without complete disassembly.
Removal
1. With the engine removed from the vehicle,
remove the clutch assembly (if equipped) and
flywheel. Mount engine in stand and clamp
securely.