PONTIAC FIERO 1988 Service Repair Manual

6E3-C2-6 2.8L (VIN 5) DRIVEABILITY AND EMISSIONS
FUEL RAIL ASSEMBLY
Figure C2-6 Plenum and Fuel Rail Removal
Important
At any time the fuel system is opened for service,
the O-ring seals used with the related
component(s) should be replaced.
Remove or Disconnect
1. Negative battery cable.
2. Plenum.
3. Fuel lines.
4. Cold start valve.
5. Vacuum line at pressure regulator.
6. Fuel rail retaining bolts
7. Injector harness connectors.
8. Rail and injectors.
install or Connect
1. Coat injector "On-rings with engine oil.
2. Rail and injectors.
3. Injector harness.
4. Fuel rail retaining bolt.
5. Vacuum line at pressure regulator.
6. Cold start valve.
7. Fuel lines.
8. Plenum.
9. Negative cable
10. Cycle the ignition on and off several times and
inspect fuel system for leaks.
FUEL RAIL SERVICE
Names of component parts will be found on the
numbered list that accompanies the exploded view
(Figure C2-9). Numbers used to identify parts on the
exploded view will identify the same parts in other
illustrations of this section.
An eight digit identification number is stamped
on the side of the fuel rail assembly, as shown in
Figure C2-7. Refer to this number if servicing or part
replacement is required.
Figure C2-7 Fuel Rail Assembly [dentification
UNIT SERVICE PROCEDURES
Important
When servicing the fuel rail assembly,
precautions must be taken to prevent dirt and
other contaminants from entering the fuel
passages. It is recommended that fittings be
capped, and holes be plugged, during servicing.

DRIVEABILITY AND EMISSIONS 2.8L (VIN S) 6E3-CZ-7
100 VALVE - COLD START
101 TUBE AND BODY ASSEMBLY
102 O-RING SEAL -VALVE
103 O-RING SEAL - BODY
104 O-RING SEAL -TUBE
Figure C2-8 Cold Start Valve Assembly
important
At any time the fuel system is opened for service,
the O-ring seals used with related
component(s)
should be replaced.
a Cleaning and a Inspection
Before disassembly, the fuel rail assembly may be
cleaned with a spray type engine cleaner, such as AC
Delco X-30A or equivalent, following package
instructions. The fuel rail should not be immersed in
liquid solvent.
COLD START TUBE AND VALVE ASSEMBLY
(Figure C2-8)
Remove or Disconnect
1. Negative battery cable.
2. Plenum.
3. Distributor cap.
4. Cold start valve retaining bolts.
5. Tube from rail.
Clean
@ Areas around valve and connection with AC Delco
X-30A or equivalent.
@ Valve from tube and body assembly (101).
@ Bend tab back to permit unscrewing of valve.
@ Adjust
1. Turn valve completely into body.
2. Turn valve back one full turn, until electrical
connector is at top position.
3. Bend tang of body forward to limit rotation of
valve to less than
a full turn.
Install or Connect
1. New valve O-ring seal (102) and body O-ring seal
(103), on cold start valve (100).
2. Tube O-ring seal (104) on tube and body assembly
(101).
3. Cold start valve in body assembly.
4. Distributor cap.
5. Plenum.
6. Negative battery cable.
FUEL PRESSURE CONNECTION ASSEMBLY
(Figure
C2-I 0)
Remove or Disconnect
1. Negative battery terminal.
Clean
@ Area around valve and connection with AC
Delco X-30A or equivalent.
2. Fuel pressure connection assembly (26) and seal
(27). Discard seal.
Install or Connect
1. New seal (27) on fuel pressure connection
assembly
(26).
2. Fuel pressure connection assembly in fuel rail.
Tighten
@ Fuel pressure connection assembly to 10.0
N.m (88.0 in lbs.)
3. Negative battery terminal.
a inspect
@ Energize fuel pump and check for leaks.

6E3-C2-8 2.8L (VIN S) DRIVEABILITY AND EMISSIONS
Bart Name
0-ring-Fuel
Inlet Line
0-ring-Fuel Return Line
Fuel Rail and Pressure Regulator
Seal-Fuel Block Clip-injector Retainer
100 Valve-Cold Start
101 Tube and Body Assembly
102 0-Ring Seal-Valve
103 0-Ring Seal-Body
104 0-Ring Seal-Tube
105 Fitting-Cold Start
I I I
I I
I
1 I
I
I
I
I
I

DRIVEABILITY AND EMISSIONS 2.8L (VIN S) 6E3-C2-9
26 FUEL PRESSURE CONNECTION ASSEMBLY
27 SEAL - FUEL PRESSURE CONNECTION ASSEMBLY
28 CAP - FUEL PRESSURE CONNECTION ASSEMBLY
55 FUEL BLOCK
Figure C2-10 Fuel Pressure Connection Assembly
FUEL BLOCK AND SEAL
Figure CZ-I 1
Remove or Disconnect
1. Negative battery terminal.
2. Engine components above fuel block.
I O-RING -FUEL INLET 2 O-RING . FUEL RETURN 11 FUEL RAlL ASSEMBLY 55 FUEL BLOCK 56 SEAL -FUEL BLOCK 57 SCREW ASSEMBLY - FUEL BLOCK ATTACHING 55 1461-6E
Figure C2-11 Fuel Block Assembly
Clean
@ Fuel block (55) and adiacent fuel line
connections with
AC ~elco X-30A or
equivalent.
3. Fuel inlet and return lines, and O-ring seals (1)
and (2).
- Discard O-ring seals.
4. Fuel block attaching screw assemblies
(57).
5. Fuel block (55) and seal (56). Discard seal.
FUEL RAlL
REL
85 INJECTOR -PORT
87 CLIP-INJECTOR RETAINER
Figure C2-12 Injector Removal
- @ Sealing surfaces of fuel block and fuel rail
assembly to ensure a good seal.
Install or Connect
1. New fuel block sea1 (56) on fuel rail assembly ( 1 I).
2. Fuel block (55) on seal.
3. Fuel block attaching screw assemblies (57).
Tighten
@ Attaching screw assemblies to 5.0 Nm (44.0
in. Ibs.
)
4. New O-ring seals (1) and (2) on fuel inlet and
return lines.
5. Fuel inlet and return lines.
6. Battery negative terminal.
Inspect
@ Energize fuel pump and check for fuel leaks
FUEL INJECTORS
Each port injector is located and held in position
by a retainer clip that must be rotated to release
and/or lock the injector in place, as shown in Figure
C2-12.
Port Injectors with lnjector Retaining Clips
Remove or Disconnect
1. Rotate injector retaining clip(s) (87) to unlocked
position.
2. Port in*jectors (85).

6E3-C2-10 2.8L (VIN 5) DRIVEABILITY AND EMISSIONS
Inspect
@ All injector O-ring seals (86).
- Replace if damaged.
+++ Assemble [7]
e New O-ring seals (86) as required, on port
i~,jectors (85).
lnstall or Connect
1. Lubricate all injector O-ring seals with engine oil.
2. Port injectors to fuel rail and pressure regulator
assembly
(11).
3. Rotate injector retainer clips (87) to locking
position (Figure C2-12).
Fuel Pressure Regulator
Important
The pressure regulator is factory adjusted and is
not serviceable. Do not attempt to remove the
regulator from the fuel rail.
PORT INJECTORS
Each port injector is located and held in position
by
a retainer clip that must be rotated to release
and/or lock the injector in place, as shown in Figure
C2-13.
FUEL RAIL
85 INJECTOR - PORT
87 CLIP-INJECTOR RETAINER
Figure C2-13 Port lnjector with Injector Retainer Clip
Remove or Disconnect
1. Rotate injector retaining clip(s) (87) to unlocked
position.
2. Injectors
(85).
inspect
@ All injector O-ring seals (86).
- Replace if damaged.
Assemble
@ New O-ring seals (86) as required, on injectors
(85).
Install or Connect
1. Lubricate all injector O-ring seals with engine oil.
2. Injectors
t,o fuel rail and pressure regulator
assembly
(1 1).
3. IZotate injector retainer clips (87) to locking
position (Figure
C2-13).
240PWESSUREREGULATORAND
BASE ASSEMBLY
Figure C2-14 Fuel Pressure Regulator
PRESSURE REGULATOR
Figure
C2-14
important
The pressure regulator is factory adjusted and is
not serviceable.
DO not attempt to remove
regulator cover.
a Remove or Disconnect
1. Front crossover tube rc1;ainer attaching screw
assembly
(235) anri c~-~):,so irer tube retainer (234j.
2. Retainer to base screlv sssembly !273) and re:i!:
crossover tube ret,ai nclr I2701
3. Separate the left hand fuel rail and plug assembly
(200) from the rigl~f, hand fuel rail and tube
assembly
(220).
4. Bracket to rail attaching screw assembly (2561,
bracket to hase attaching screw assembly (258)
and the pressure regulator and base assembly
bracket
(255).
5. Rear hracket attaching study assembly (222).
6. Base to right hancl rail screw assembly (275).

DRIVEABILITY AND EMISSIONS 2.8L (VIN 5) 6E3-CZ-1 l
7. Pressure
regulator and base assembly (240) from
right hand rail assembly (220).
8. Rotate the regulator and base assembly to remove
from the fuel outlet tube.
9. Base to rail connector (250).
Important
When removing 0-Ring seals, note locations and
sizes, to assure correct replacement and re-
assembly.
10. 0-Ring seals:
@ Connector (252).
@ Fuel outlet tube (224).
@ Rear crossover tube (267).
@ Front crossover tube (232).
Install or Connect
1. Lubricate with engine oil, and install 0-Ring
seals:
@ Connector (252).
@ Fuel outlet tube (224).
@ Rear crossover tube (267).
@ Front crossover tube (232).
2. Base
to rail connector (250) in pressure regulator
and base assembly
(240).
3. Regulator and base assembly on fuel outlet tube.
4. Rotate the regulator and base assembly to install
base to rail connector (250) into right hand rail
assembly.
5. Base
to right hand rail screw assembly
(275).
6. Pressure
regulator and base assembly bracket
(255), bracket to base attaching screw assembly
(258) and bracket to rail attaching screw assembly
(256).
7. Rear bracket attaching study assembly (222).
8. Left hand rail and plug assembly (200), with front
and rear crossover tubes (230) and
265), to right
hand rail and tube assembly (220).
9. Rear crossover tube retainer (270) and retainer to
base screw assembly (273).
10. Front crossover tube retainer
(234) and retainer
attaching screw assembly
(235).
COLD START FUEL INJECTION SWITCH
Remove or Disconned
1. Connector.
2. Switch.
n Install or Connect
1. Switch.
2. Connector.
THROTTLE BODY
(Figure
C2-15)
Remove or Disconnect
1. Air inlet duct.
2.
IAC and TPS connectors.
3. Vacuum lines.
4. Coolant hoses (2).
5. Throttle, TV and cruise control cables
6. Throttle body retaining bolts.
Install or Connect
1. Reverse procedure to reinstall.
2. Refill
radiator with lost coolant.
THROTTLE BODY ASSEMBLY
Figure C2-15 Throttle Body Service
THROTTLE BODY SERVICE IDENTIFICATION
An eight digit identification number is stamped
on the throttle body casting next to the coolant cover,
as shown in Figure C2-16. Refer to this model
identification number if servicing or part replacement
is required.
Names of component parts will be found on the
numbered list that accompanies the exploded view
(Figure C2-17). Numbers used to identify parts in the
exploded views also are used to identify the same parts
in other illustrations of this manual.
IDENTIFICATION NUMBER
Figure C2-16 Throttle Body Identification

DRIVEABILITY AND EMISSIONS 2.8L (VIN S) 6E3-C2-13
PARTS INFORMATION
PART NAME PART #
............................................. Throttle Body Assembly 10
............................................... . Plug Idle Stop Screw 15
........................................... Screw Assembly . Idle Stop 16
.............................................. . Spring
Idle Stop Screw 17
........................................ Sensor -Throttle Position (TPS) 20
....................................... Screw Assembly . TPS Attaching 21
....................................... Retainer . TPS
Attaching Screw 22
............................................... . Cover Coolant
Cavity 40
............................... Screw Assembly . Coolant Cover Attaching 45
................................. . 0-Ring
Coolant Cover to Throttle Body 46
............................... Idle AirIVacuum Signal Housing
Assembly 60
........................ Screw Assembly . Idle AirIVacuum Signal
Assembly 65
........................ Screw Assembly . Idle AirIVacuum Signal
Assembly 66
............................... . Gasket
Idle Air/Vacuum Signal Assembly 67
................................. . Valve Assembly Idle Air Control (IAC) 70
......................................... . Gasket IAC Valve Assembly 71

6E3-CZ-14 2.8L (VIN S) DRlVEABlLlTV AND EMISSIONS
MINIMUM IDLE SPEED ADJUSTMENT
The idle stop screw (16), used to regulate
minimum idle speed of the engine, is adjusted at the
factory, then is covered with a plug
(15) to discourage
unnecessary readjustment. However,
if it is necessary
to gain access to the idle stop screw assembly, proceed
as shown in Figure C2-18.
Adjust
1. Pierce
the idle stop screw plug (15) with an awl,
and apply leverage to remove it.
2. Adjust idle
stop screw assembly (16) as required.
3. With IAC motor connected, ground diagnostic
lead.
4. Turn "ON" ignition, do not start engine. Wait at
least 30 seconds.
5. With ignition "ON," disconnect IAC electrical
connector.
6. Start engine and allow to go "Closed Loop".
7. Remove ground from diagnostic terminal.
8. Adjust idle stop screw to 550 rpm in drive, 650 rpm
in neutral on manual transmission vehicles.
9. Turn ignition "OFF7' and reconnect connector at
IAC motor.
10.
110 not adjust TPS unless setting is outside of 0.35-
0.67 limits. If adjustment is required, see
procedure in Section
"6l33-Cl".
11. Start engine and inspect for proper idle operation.
IDLE STOP
SCREW
ASSEtVIBLY
SCREW PLUG
* 55 1503-6E
Figure C2-18 Removing ldle Stop Screw Plug
UNIT REPAIR PROCEDURES
The unit repair procedures cover component
replacement with the unit on the vehicle. However,
throttle body replacement requires that the
complete unit be removed from the engine. If
removed, it may be placed on a holding fixture, such as
5-9789-118, BT-3553, or equivalent, to prevent
damage to the throttle valve.
Cleaning and Inspection
Throttle body parts, except as noted below, may be
cleaned in
a cold immersion-type cleaner such as AC
Delco X-55 or equivalent.
NOTICE: The throttle position sensor (TPS), idle air
control
(IAC) valve, throttle body with
cover and seals or gaskets in place, should
NOT be soaked in liquid solvent or
cleaner, as they may be damaged. If TPS
or IAC valve is still mounted in the
throttle body, do not immerse throttle
body.
1. Clean
all metal parts throughly and blow dry with
shop air. Be sure all air passages are free of burrs
and dirt.
2. Inspect mating casting surfaces for damage that
could affect gasket sealing.
IDLE AIR CONTROL VALVE ASSEMBLY AND
GASKET
(Figure
CZ-19)
Remove or Disconnect
1. Electrical connector at idle air control valve
assembly
(70).
2. IAC valve assembly from idle airlvacuum signal
housing assembly
(60).
3. IAC valve assembly gasket (71) and discard.
60 IDLE AIRIVACUUM SIGNAL HOUSING
70 IDLE AIR CONTROL VALVE
(IAC)
71 IAC GASKET
Figure C2-19 ldle Air Control Valve Assembly

DRIVEABILITY AND EMISSIONS 2.8L (VIN S) 6E3-CZ-15
NOTICE: Before instal ling new idle air control valve
assembly, the position of its pintle
MUST
be checked. If pintle is extended too far,
damage to the assembly may occur.
Measure
@ Distance from gasket mounting surface of IAC
valve assembly
(70) to tip of pintle, Dimension
"A" in Figure
C2-19.
Adjust
If distance is greater that 28 mm (1 118 in.), reduce -
it as follows:
a. If
IAC valve assembly has
a "collar" around
electrical connector end, use firm hand pressure
on pintle to retract it. (A slight side-to-side motion
may help.)
b. If IAC valve assembly has "no collar", compress
pintle-retaining spring toward body of the IAC
and try to turn pintle clockwise.
@ If pintle will turn, continue turning until
28mm
(1 118 in.) is reached. Return spring to
original position, with straight part of spring
end lined up with flat surface under the pintle
head.
@ If pintle will not turn, use firm hand pressure
to retract it.
Install or Connect
1. New IAC valve assembly gasket (71) on IAC valve
assembly
(70).
2. IAC valve assembly in idle airlvacuum signal
housing assembly
(60).
Tighten
IAC valve assembly to 18N.m (13 ft. Ibs.), with
wrench on hex surface only.
3. Electrical connector at IAC valve assembly (70).
Important
No physical adjustment is made to the IAC
assembly after installation.
IAC resetting occurs
after reinstallation on the vehicle, and is reset
after the engine is started and then the ignition
turned off.
IDLE AIR / VACUUM SIGNAL HOUSING
ASSEMBLY
(With
IAC Removed) (Figure C2-20)
Remove or Disconnect
1. Idle airlvacuurn signal assembly attaching screw
assemblies
(65) and (66).
2. Idle airlvacuum signal housing assembly (60).
3. Idle airlvacuum signal assembly gasket (67).
10 THROTTLE BODY ASSEMBLY
60 IDLE AIWVACUUM SIGNAL
HOUSING ASSY
65 SCREW ASSY - IDLE AIWVACUUM SIGNAL
HOUSING ASSY.
66 SCREW
ASSY
- IDLE AIWVACUUM SIGNAL
HOUSING ASSY
67 GASKET - IDLE AIR VACUUM SIGNAL ASSY 70 VALVE ASSY - IDLE AIR CONTROL (IAC) 71 GASKET - IAC VALVE ASSY
Figure C2-20 Idle AirIVacuum Signal Housing
Assembly
Tighten
@ Attaching screw assemblies (starting in center
and
moving outward) to 3.0 N.m (27.0 in. Ibs.).
COOLANT CAVITY COVER AND O-RING
(Figure
C2-21)
Remove or Disconnect
1. Coolant cover attaching. screw assemblies (45).
2. Coolant cavity cover (40).
3. Coolant cover to throttle body O-ring (46).
Inspect
@ Gasket and O-ring surfaces, for damage and
corrosion which might effect sealing.
Install and Connect
1. Lubricate coolant cover to throttle body O-ring (46)
with ethylene glycol antifreeze.
2. O-ring in throttle body assembly (10).
:3. Coolant cavity cover.
4. Coolant cover attaching screw assemblies (451,
applying pressure against throttle body (1 0).