PONTIAC FIERO 1988 Service Repair Manual

6A3-2 V-8 ENGINE
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 pivots on its ball and transmits the
camshaft motion to the valve. The rocker-arm ball is
retained by a nut.
HYDRAULIC VALVE LIFTERS
Hydraulic Valve Lifters are used to keep all parts
of the valve train in constant contact.
The hydraulic lifter assembly consists of: a roller,
the lifter body, which rides in the cylinder block boss,
a plunger, a push rod seat, a metering valve, a plunger
spring, a check ball and spring, a check ball retainer
and a push rod seat retainer.
When the lifter is riding on the low point of the
cam, the plunger spring keeps the plunger and push rod
seat in contact with the push rod.
When the lifter body begins to ride up the cam
lobe, the check ball cuts off the transfer of oil from the
reservoir below the plunger. The plunger and lifter
body then rise as a unit, pushing up the push rod and
opening the valve.
As the lifter body rides down the other side of the
cam, the plunger follows with it until the valve closes.
The lifter body continues to follow the cam to its low
point, but the plunger spring keeps the plunger in
contact with the push rod. The ball check valve will then
move off its seat and the lifter reservoir will
remain full.
INTAKE MANIFOLD
The intake manifold for those engines with
carburetors are made of cast iron or aluminum double
level design for efficient fuel distribution. An Exhaust
Gas Recirculation (EGR) port is also cast into the
manifold for the mixture of exhaust gases with the fuel
air mixture.
The intake manifold for those vehicles equipped
with
PFI is a cast aluminum unit. It centrally supports
a fuel rail with
8 fuel injectors.
EXHAUST MANIFOLDS
Two cast iron exhaust manifolds are used to
direct exhaust gases from the combustion chambers to
the exhaust system. The left hand side manifold
receives a heat shield that is used to route heated air
to the air cleaner. for better fuel vaporization during
warm-up.
COMBUSTION CHAMBERS
Combustion Chambers are cast to insure uniform
shape for all cylinders. Spark plugs are located between
the intake and exhaust valves. The contoured wedge
shape of the combustion chamber minimizes the
possibility of detonation, facilitates breathing and
provides swirling turbulence for smooth, complete
combustion.
ENGINE LUBRICATION
Full pressure lubrication through a full flow oil through drilled passages, to the camshaft and
filter, is furnished by a gear-type oil pump. The crankshaft to lubricate the bearings. The valve lifter oil
distributor, driven by a helical gear on the camshaft,
gallery feeds the valve lifters which, through hollow
drives the oil pump. The main oil gallery feeds oil,
push rods, feed the individually mounted rocker arms.

V-8 ENGINE BA3-5
ON-VEHICLE SERVICE
Fig. 6A3-3 Engine Mounts
POWERTRAIN MOUNTS
Engine mounts (fig. 6A3-3) are the
non-adjustable type and seldom require service.
Broken or deteriorated mounts should be replaced
immediately, because of the added strain placed on
other mounts and drive line components.
Checking Engine Mounts
Front Mount
Raise the engine to remove weight from the
mounts and to place a slight tension in the rubber.
Observe both mounts while raising engine. If an engine
mount exhibits:
a. Hard rubber surface covered with heat
check cracks;
b. Rubber separated from a metal plate of the
mount;
c. Rubber split through center
replace the mount. If there is relative movement
between a metal plate of the mount and its attaching
points, lower the engine on the mounts and tighten the
screws or nuts attaching the mount to the engine,
frame, or bracket.
Rear Mount
Raise the vehicle on a hoist. Push up and pull
down on the transmission tailshaft while observing the
transmission mount. If the rubber separates from the
metal plate of the mount or if the tailshaft moves up
but not down (mount bottomed out) replace the mount.
If there is relative movement between a metal
plate of the mount and its attaching point, tighten the
screws or nuts attaching the mount to the transmission
or crossmember.
Front Mount Replacement
1. Remove mount retaining bolt from below frame
mounting bracket.
2. Raise front of engine and remove
mount-to-engine bolts and remove mount. Raise
engine only enough for sufficient clearance.
Check for interference between rear of engine and
cowl panel.
3. Replace mount to engine and lower engine into
place.
4. Install retaining bolt and torque all bolts to
specifications.
Rear Mount Replacement I
1. Support transmission weight to relieve rear
mounts.
2. Remove crossmember-to-mount nuts.
3. Remove mount-to-transmission bolts, raise
transmission, then remove mount.
4. Install new mount on transmission.
5. While lowering transmission, align mount to
crossmember.
6. Torque bolts to specifications.

6A3-6 V-8 ENGINE
Fig. 6A3-4 Intake Manifold Installation (LO31
INTAKE MANIFOLD
Removal (TBI)
1. Disconnect battery negative cable.
2. Drain radiator and remove air cleaner.
3. Disconnect:
e Radiator upper hose and heater hose at
manifold.
e TBI linkage.
e Fuel lines
Spark plug wires (right side).
e Necessary wires and hoses.
4. Remove distributor cap and mark rotor position
with chalk, then remove distributor.
5. Remove (as required) air compressor and
brackets and cruise control servo and bracket.
6. Remove generator upper mounting bracket.
7. Remove EGR solenoids and bracket.
8. Remove vacuum brake line.
9. Remove manifold attaching bolts, then remove
manifold, discard gaskets.
10. If manifold is to be replaced, transfer:
e TBI attaching bolts, where applicable.
Thermostat with housing (use new gasket or
RTV, as applicable).
EGR Valve (use new gasket), where
applicable.
e Necessary switches and fittings.
lnstallation
1. Clean gasket and seal surfaces on manifold,
block, and cylinder heads with degreaser.
Remove all RTV that is loose or will cause
installation interference.
2. Install gaskets on cylinder heads and place a
3/16" (5mm) bead of RTV, At1052917 or
equivalent, on the front and rear ridges of the
cylinder case. Extend the bead
1/2" (13mm) up
each cylinder head to seal and retain the manifold
side gaskets. Use sealer at water passages. 3.
Install manifold and torque bolts to specifications
in the sequence outlined in
fig. 4.
4. Install (if removed) air compressor and bracket,
and cruise control servo and bracket.
5. Install distributor, positioning rotor at chalk
mark, then install distributor cap.
6. Install generator upper mounting bracket.
7. Install vacuum brake line.
8. Install EGR solenoid and bracket.
9. Connect:
Fuel lines
s Accelerator linkage at carburetor.
@ Disconnected wires and hoses.
Battery negative cable at battery.
10. Install air cleaner.
11. Fill with coolant, start engine, adjust ignition
timing
and check for leaks.
SNUG TIGHTENING SEQUENCE
WEW @
AT TIME OF INSTALUVIBN SURFACE AR- MUST BE FREE OF OIL AND 8ULlNG CQMWUIJD MUST BE Wm TO TOUCH WHEN BBLTISCRWS ARE TORQUED. APPLY SULINO GOMPOLINB
Figure 6A3-4a Intake Manifold Installation (PFI)
Removal (PFI]
1. Disconnect the negative battery cable.
2. Drain the cooling system.

V-8 ENGINE 6A3-7
-
3. Disconnect accelerator T.V. and cruise cables.
4. Remove air intake duct.
5. Disconnect coolant hoses at throttle body.
6. Disconnect wires at throttle body.
7. Disconnect vacuum and breather hoses at
throttle body.
8. Remove throttle body from plenum.
9. Remove distributor shield.
10. Disconnect brake vacuum hoses at plenum.
1 1. Disconnect vacuum hoses at plenum.
12. Refer to Section 6E3 for removal of:
a Plenum
Fuel Rail
a Cold Start Injector
e Runners
13. Remove distributor.
14. Disconnect EGR solenoid.
15. Disconnect all electrical wires that would
interfere.
16. Remove intake manifold bolts.
17. Remove intake manifold.
Installation
1. Clean all seal surfaces.
2. Install gaskets and place a 3/16 inch 5 (mm) bead
of RTV, No. 1052917 or
equivalent,on the front
and rear ridges of the cylinder case. Extend the
bead 1/2 inch
(13mm) up each cylinder head to
seal and retain the manifold side gaskets and
install intake manifold.
3. Torque manifold bolts to specified torque.
4. Reconnect electrical and vacuum wires.
5. Install distributor.
6. Refer to Section 6E3 for installation
of:
e Plenum
e Fuel Rail
e Cold Start Injectors
a Runners
7. Vacuum hoses at plenum.
8. Install distributor shield.
9. Install throttle body and related parts.
10. Fill cooling system.
1 1. Reconnect battery cable.
12. Start engine and look for leaks.
DIPSTICK TUBE
Removal
1.
Disconnect battery negative cable to prevent
possible contact of the dipstick tube with the
battery terminal on starter during removal.
2. Remove bolt attaching bracket to engine and
remove tube (loose fit).
lnstallation
1. Clean tube and apply sealant #I052080 or
equivalent, around tube
1/2" below bead.
2. Insert tube in block and rotate into position.
3. Install bolt (with starter brace on top of tube
bracket) and connect battery cable.
&LB9/LO3/L98
19-35 N.m (14-26 FT. LBS.)
27-43
N.m (20-32 FT. LBS.)
Fig. 6A3-5 Exhaust Manifold lnstallation
EXHAUST MANIFOLD
Removal (Right Side)
1. Disconnect battery negative cable.
2. Disconnect spark plug wires.
3. Disconnect
A.I.R. hoses.
4. Remove air management valve.
5. Raise vehicle.
6. Remove exhaust pipe nuts.
7. Lower vehicle.
8. Remove manifold bolts.
9. Remove exhaust manifold.
lnstallation
1. Clean
mating surfaces on manifold and head,
then install manifold in position and install bolts
finger tight.
2. Torque bolts to specifications.
3. Reverse removal procedures.
Removal (Left Side)
1. Disconnect battery negative cable.
2. Disconnect spark plug wires.
3. Disconnect A.I.R. hoses.
4. If equipped with
A/C, remove compressor and
lay aside.
5. Remove power steering pump and lay aside.
6. Loosen brackets.
7. Remove rear
A/C and power steering adjusting
bracket.
8. Remove lower power steering adjusting bracket.
9. Raise vehicle.

6A3-8 V-8 ENGINE
10. Remove exhaust pipe nuts.
1 1. Lower vehicle.
12. Remove manifold bolts.
13. Remove manifold.
Installation
1. Clean mating surfaces on manifold and head,
then install manifold in position and install bolts
finger tight.
2. Torque bolts to specifications.
3. Reverse removal procedures.
4. Adjust necessary drive belts.
P
IN.)
Fig. 6A3-6 Rocker Arm Cover
ROCKER ARM COVER (FIG. 6A3-6)
Removal (Right Side)
1. Disconnect battery negative cable.
2. Remove air cleaner if equipped.
3. Disconnect air management hoses.
4. Disconnect wires and hoses.
EGR solenoid.
e Alternator
5. Remove EGR solenoid.
6. Remove air management valve bracket and move
aside.
7. Remove air management tubes.
8. Remove cover bolts.
9. Remove cover.
N OTI G E: If cover adheres to cylinder head, shear
off by bumping end of rocker arm cover with a
block of wood and a rubber mallet. If cover still
will not come loose, CAREFULLY pry until
loose. DO NOT DISTORT SEALING
FLANGE.
Removal (Left Side)
1. Disconnect battery negative cable.
2. Remove air cleaner if equipped.
3. Remove Power brake booster line.
4. isc connect A.I.R. hoses.
5. Disconnect PCV and move wire harness.
6. Remove cover bolts.
7. Remove cover.
NOTICE: If cover adheres to cylinder head, shear
off by bumping end of rocker arm cover with a
block of wood and a rubber mallet. If cover still
will not come loose, CAREFULLY pry until
loose. DO NOT DISTORT SEALING
FLANGE.
lnstallation
1. Clean gasket surface on cylinder head and rocker
arm cover.
2. Inspect rocker arm cover for damage or
distortion and replace cover if necessary.
3. Install a new gasket.
4. Reverse removal procedures.
5. Start engine and check for leaks.
6-14 N.m RESTRICTOR
(55-125 IN.
LB.) 161 13-19 N,rn - 1 RETAINER (10-14 FT. LBS.)
/ PUSH ROD a BALL
a LIFTER 1 ROCKER ARM
Fig. 6A3-7 Rocker Arm and Pushrods
ROCKER ARM AND PUSHRODS
Removal
1. Remove rocker arm covers as previously
outlined.
2. Remove rocker arm nuts, rocker arm balls,
rocker arms and push rods. Place rocker arms,
rocker arm balls and push rods in a rack to they
may be reinstalled in the same locations.
Installation and Adjustment
e Whenever new rocker arms and/or rocker
arm balls are being installed, coat bearing

V-8 ENGINE 6A3-9
surfaces of rocker arms and rocker arm balls
with "Molykote" or its equivalent.
1. Install push rods.
Be sure push rods seat in lifter
socket.
2. Install
rocker arms, rocker arm balls and rocker
arm nuts. Tighten rocker arm nuts until all lash
is eliminated.
3. Adjust
valves when lifter is on base circle of
camshaft lobe as follows:
a. Crank engine until mark on torsional
damper lines up with center or
"0" mark on
the timing tab fastened to the crankcase
front cover and the engine is in the
#l
firing position. This may be determined by
placing fingers on the
# 1 valve as the mark
on the damper comes near the
"0" mark on
the crankcase front cover. If the valves are
not moving, the engine is in the
# 1 firing
position. If the valves move as the mark
comes up to the timing tab, the engine is in
#6 firing position and should be turned
over one more time to reach the
#1
position.
b. With
the engine in the
# 1 firing position as
just determined, the following valves may be
adjusted:
e Exhaust--1, 3, 4, 8
e Intake--1, 2, 5, 7
, ,
Fig. 6A3-8 Valve Adjustment - Typical
c. Back out adjusting nut until lash is felt at
the push rod then turn in adjusting nut until
all lash is removed. This can be determined
by rotating push rod while turning adjusting
nut (fig.
6A3-8). When play has been
removed, turn adjusting nut
1 + 1/4 in
additional turn (to center lifter plunger).
d. Crank
the engine one revolution until the
pointer
"0" mark and torsional damper
mark are again in alignment. This is
#6
firing position. With the engine in this
position the following valves may be
adjusted.
e Exhaust--2, 5, 6, 7
o ntake--3, 4, 6, 8
4. Install rocker arm covers as previously outlined.
5. Start engine and adjust carburetor idle speed, if
needed.
VALVE STEM OIL SEAL AND/OR VAL\/E
SPRING (6A3-9)
INTAKE VALVE DETAIL
EXHAUST VALVE DETAIL
Fig. 6A3-9 Valve Seals
Fig.
6A3-10 Compressing Valve Spring
Removal
1. Remove rocker arm cover as previously outlined.
2. Remove
spark plug, rocker arm and push rod on
the
cylinder(s) to be serviced.
3. Install air line adapter Tool J-23590 to spark plug
port and apply compressed air to hold the valves
in place.
4. Using Tool J-5892 to compress the valve spring,
remove the valve locks, valve cap and valve
spring and damper (fig.
6A3-10).
5. Remove
the valve stem or head oil seal.

QA3-10 V-8 ENGINE
lnstallation
1. Install valve stem seal over valve stem and seat
against head.
2. Set
the valve spring and damper, oil shedder and
valve cap in place. Compress the spring with Tool
J-5892 and install oil seal in the lower groove of
the stem, making sure the seal is flat and not
twisted. A light coat of oil on the seal will help
prevent twisting.
3. Install
the valve locks and release the compressor
tool making sure the locks seat properly in the
upper groove of the valve stem. Grease may be
used to hold the locks in place while releasing the
compressor tool.
4. Using tool J-23994, apply vacuum to the valve
cap to make sure no air leaks past the seal.
5. Install spark plug and torque to 22 lb. ft.
(30N.m).
6. Install and adjust valve mechanism as previously
outlined.
VALVE LIFTERS
Hydraulic valve lifters very seldom require
attention. The lifters are extremely simple in design,
readjustments are not necessary, and servicing of the
lifters requires only that care and cleanliness be
exercised in the handling of parts.
Valve Lifter Diagnosis
1.
Momentarily Noisy When Car is Started:
This condition is normal. Oil drains from the
lifters which are holding the valves open when the
engine is not running. It will take a few seconds
for the lifter to fill after the engine is started.
2. Intermittently Noisy On Idle Only. Disappearing
When Engine Speed is Increased:
Intermittent clicking may be an indication of a
pitted check valve ball, or it may be caused by
dirt.
Correction: Clean the lifter and inspect. If check
valve ball is defective, replace lifter.
3. Noisy At Slow Idle Or With Hot Oil, Quiet With
Cold Oil Or As Engine Speed Is Increased:
High leak down rate. Replace suspect lifter.
4. Noisy At High Car Speeds And Quiet At Low
Speeds:
a. High oil level
- Oil level above the "Full"
mark allows crankshaft counterweights to
churn the oil into foam. When foam is
pumped into the lifters, they will become
noisy since a solid column of oil is required
for proper operation. Correction: Drain oil
inti1 proper level is obtained.
b. Low oil level - Oil level below the "Add"
mark allows the pump to pump air at high
speeds which results in noisy lifters.
Correction: Fill until proper oil level is
obtained.
c. Oil pan bent on bottom or pump screen
cocked or loose, replace or repair as
necessary. 5.
Noisy At Idle Becoming Louder As Engine Speed
Is Increased To 1500 rpm:
This noise is not connected with lifter
malfunction. It becomes most noticeable in the
car at 10 to 15 mph "1" (Low) range, or 30 to
35
mph "DM (Drive) range and is best described as
a
hashy sound. At slow idle, it may be entirely
gone or appear as a light ticking noise in one or
more valves. It is caused by one or more of the
following:
a. Badly worn or scuffed valve tip and rocker
arm pad.
b. Excessive valve stem to guide clearance.
c. Excessive valve seat
runout.
d. Off square valve spring.
e. Excessive valve face
runout.
f. Valve spring damper clicking on rotator.
Removal
1.
Remove intake manifold as previously outlined.
2. Remove valve mechanism as previously outlined.
3. Remove valve lifter retainer.
4. Remvoe valve lifter restrictor.
5. Remove valve lifters (Fig.
6A3-7). Place valve
lifters in a rack so that they may be reinstalled in
the same location.
Installation
1.
Coat roller of valve lifters with "Molykote" or its
equivalent and install valve lifters.
2. Install valve lifter restrictor.
3. Install valve lifter retainer.
4. Install intake manifold as previously outlined.
5. Install and adjust valve mechanism as outlined.
Disassembly
PLUNGER SPRING
Fig. 6A3-1 1 Hydraulic Valve Lifter
1. Hold the plunger down with a push rod, and
using the blade of a small screw driver, remove
the push rod seat retainer.
2. Remove the push rod seat and metering valve
(fig.
6A3- 1 1).

V-8 ENGINE BA3-11
Fig. 6/43-12 Removing Ball Check Valve Typical
3. Remove the plunger, ball check valve assembly
and the plunger spring.
4. Remove
the ball check valve and spring by prying
the ball retainer loose from the plunger with the
blade of a small screw driver (fig.
6A3-12).
Cleaning and Inspection
Thoroughly clean all parts in cleaning solvent,
and inspect them carefully. If any parts are damaged
or worn, the entire lifter assembly should be replaced.
1. Lifter body for:
@ Wear
e Scuffing. Also inspect the bore in the
cylinder block.
@ Flat spot on the bottom. If the bottom is
worn flat or grooved, replace the lifter. Also
inspect the camshaft lobe.
2. Roller for:
@ Freedom of movement. Replace the lifter if
it binds or roughness can be felt.
@ Excessive looseness in the roller bearings.
Replace lifter if necessary.
e Flat spots. Replace the lifter, if worn.
e Pitting, replace the lifter if pitted.
3.
Pushrod seat. If worn, inspect the pushrod.
Replace the pushrod, if worn.
Assembly
1. Place the check ball on small hole in bottom of
the plunger.
2. Insert check ball spring on seat in ball retainer
and place retainer over ball so that spring rests on
the ball. Carefully press the retainer into position
in plunger with the blade of a small screw driver
(fig.
6A3- 13).
3. Place the
plunger spring over the ball retainer and
slide the lifter body over the spring and plunger,
being careful to line up the oil feed holes in the
lifter body and plunger.
4. Fill the assembly with SAE 10 oil, then insert the
end of a
1/8" (3mm) drift pin into the plunger
and press down solid. Do not attempt to force or
pump the plunger. At this point, oil holes in the
Fig. 6A3-13 Installing Ball Check Valve Typical
lifter body and plunger assembly will be aligned
(fig. 15).
Fig. 6A3-14 Assembling Hydraulic Lifter Typical
5. Insert a
1/16" drift pin through both oil holes to
hold the plunger down against the lifter spring
tension (fig.
6A3-14).
6. Remove
the 1/8" drift pin, refill assembly with
SAE 10 oil.
7. Install the metering valve and push rod seat (fig.
6A3-11).
8. Install the push rod seat retainer, press down on
the push rod seat and remove the 1/16" drift pin
from the oil holes. The lifter is now completely
assembled, filled with oil and ready for
installation. Before installing lifters, coat the
bottom of the lifter with "Molykote" or its
equivalent.
CYLINDER HEAD ASSEMBLY (FIG. 6A3-15)
Removal
1. Remove intake manifold as previously outlined.