1988 PONTIAC FIERO belt

DRIVEABILITY AND EMISSIONS 2.8L (VIN S) 6E3-C6-4
SECTION C6
AIR INJECTION REACTlON (A.I.R.) SYSTEM
MANUAL, TRANSMISSION ONLY
CONTENTS
............... GENERAL DESCRIPTION C6-1
........................ PURPOSE C6-1
........... A.I.R. PUMP OPERATION.. C6-1
................... AIR CONTROL.. C6-1
.......... Electric Air Control Valve C6-1
............... Deceleration Valve C6-2
... RESULTS OF INCORRECT OPERATION C6-2
........................ DIAGNOSIS C6-2
............. OPERATIONAL CHECKS C6-2
.................... A.I.R. Pump C6-2
GENERAL DESCRlPTlON
PURPOSE
These systems are used to reduce carbon monoxide
(CO), hydrocarbon (HC) and oxides of nitrogen (NO,)
emissions. They also heat up the catalytic converter
quickly "ON" engine start-up so conversion of exhaust
gases will start quickly.
A.I.R. PUMP OPERATION
The system (Figure C6-1) includes:
@ An Air Pump
The air pump is driven by a belt on the front of
the engine and supplies the air to the system.
Intake air passes through a centrifugal filter fan
at the front of the pump; where foreign materials
are separated from the air by centrifugal force.
@ A Control Valve
Air flows from the pump through an
ECM
controlled valve (called a control valve) through
check valves to either the exhaust ports or the
silencer (overboard).
@ Check Valves
The check valves prevent back flow of exhaust
into the pump in the event of an exhaust backfire
or pump drive belt failure.
@ Necessary Plumbing
AIR CONTROL
Electric
Air Control Valve (EAC)
................. Hoses and Pipes C6-2
............. Deceleration Valve.. C6-3
.................... Check Valve C6-3
.................... ON-CAR SERVICE C6-3
................... DRIVE BELT ... C6-3
............... A.I.R.PUMP.....,.. C6-3
............... AIR CONTROL VALVE C6-3
.................... CHECK VALVE C6-4
............ DECELERATION VALVE.. C6-4
................ PARTS INFORMATION C6-5
ELECTRIC AIR CONTROL 1 DECELTIMING CHAMBEF VALVE 1 DIVERT AIR TO AIR
~DECEL TIMING ASSEMBLY CLEANER
VERY HIGH VACUUM 1 AIR FROM PUMP
SIGNAL PORT 1 AIR TO EXHAUST PORTS
14~~c~R1cA~~~RM1NAL 1 PRESSURE RELIEF ~SOLENOID ASSEMBLY
4s 1020-6E
Figure C6-1 - Electric Air Control Valve
When the solenoid is energized, the valve will
perform like a standardized diverter valve. Air
from
the air pump is directed to the exhaust ports, unless
there is a great sudden rise in manifold vacuum due to
throttle deceleration.
The electric air control valve combines electronic
control with the normal diverter valve function. This
valve can be electronically controlled to provide divert
air under any driving mode.

6E3-C6-2 2.8L (WIN 5) DRIVEABILITY AND EMISSIONS
When the solenoid is de-energized, the pressurized
air from the air pump is allowed to enter the decel
timing chamber. This places sufficient pressure on
the metering valve diaphragm to overcome spring
tension, closing the
valve,causing air to divert to the
silencer.
At higher engine speeds, excess air is exhausted to
the silencer through the pressure relief valve. (Figure
C6-1)
Deceleration Valve
To help prevent backfiring during high vacuum
conditions a deceleration (gulp) valve is used to allow
air to flow into the intake manifold (shown in Figure
C6-2). This air enters the airlfuel mixture to lean the
rich condition created by high vacuum when the
throttle valve closes on deceleration.
The vacuum draws the deceleration valve
diaphragm down and opens the valve allowing air
inlet duct to flow into the intake manifold.
RESULTS OF INCORRECT OPERATION
@ If no air (oxygen) flow enters the exhaust stream
at the exhaust ports, HC and
CO emission levels
will be too high.
@ Air flowing to the exhaust ports at all times could
cause
a rich ECM command and increased
temperature of the converter. This may also cause
a Code
44 due to oxygen being pumped passed the
oxygen sensor. There should be no air going to the
exhaust ports while operating in the closed loop
mode.
DIAGNOSIS
The diagnosis of the AIR system is covered in
CHART C-6 at the end of this section.
OPERATIONAL CHECKS
A.I.R. Pump
1. The air pump is a positive displacement vane type
which is permanently lubricated and requires no
periodic maintenance.
Accelerate engine to approximately
1500 rpm's
and observe air flow from
hose(s). If air flow increases
as engine is accelerated, pump is operating
satisfactorily. If air flow does not increase or is not
present, proceed as follows:
Inspect
For proper drive belt tension.
2. For a leaky pressure relief valve. Air may he
heard leaking with the pump running.
DECELERATION VALVE
1 VACUUM BLEED VALVE
1 MANIFOLD VACUUM
1 DECELERATION AIR TO INTAKE
MANIFOLD
1 FILTERED AIR FROM INTAKE DUCT
/ DIAPHRAGM
05 10 84 5s 1726-6E
Figure C6-2 - Deceleration Valve
NOTICE: If the engine or underhood compartment
is to he cleaned with
steam or high-
pressure detergent, the centrifugal filter
fan should be masked "OFF7' to prevent
liquids from entering the pump.
Inspect
3. For a seized Air Injection Pump.
3. Hoses, tubes and all connections for leaks and
proper routing.
5, For air flow from controllswitching valve.
6. AIR injection pump for proper mounting and bolt
torque.
7. If no irregularities exist and the AIR injection
pump noise is still excessive, remove and replace
pump.
CAUTION: Do Not Oil Air Pump
Hoses and Pipes
Inspect
1. Hose or pipe for deterioration or holes.
2. All hoses or pipe connections, and clamp tightness.
3. Hose or pipe routing. Interference may cause
wear

DRIVEABILITY AND EMISSIONS 2.8L (WIN 5) 6E3-C6-3
4. If a leak is suspected on the pressure side of the
system or if
a hose or pipe has been disconnected
on the pressure side, the connections should be
checked for leaks with a soapy water solution.
With the pump running, bubbles will form if
a
leak exists.
Deceleration Valve
1. Connect tachometer, start engine and allow idle to
stabilize.
2. With the engine running at specified idle speed,
remove the small deceleration valve signal hose
from the manifold vacuum source.
3. Reconnect the signal hose and listen for air flow
through the ventilation pipe and into the
deceleration valve. There should also be a
noticeable speed drop when the signal hose is
reconnected.
4. If the air flow does not continue for at least one
second or the engine speed does not drop
noticeably, check the deceleration valve hoses for
restrictions or leaks.
5. If no restrictions or leaks are found, replace the
deceleration valve.
Check Valve
Inspect
1. A check valve should be inspected whenever the
hose is disconnected form
a check valve or
whenever check valve failure is suspected.
(A
pump that had become inoperative and had shown
indications of having exhaust gases in the pump
would indicate check valve failure).
2. Blow through the check valve (toward the exhaust
manifold) then attempt to suck back through the
check valve. Flow should only be in one
direction(towax-d the exhaust manifold). Replace
valve which does not operate properly.
ON-CAR SERVICE
DRIVE BELT
Remove or Disconnect
1. Inspect drive belt for ware, cracks or deterioration
and replace if required. When installing new belt,
it must be seated and fully secured in grooves of
A/C compressor, AIR pump, generator, and
crankshaft pulleys.
A.I.R. PUMP
Remove or Disconnect
1. Hold pump pulley from turning by compressing
drive belt, then loosen pump pulley bolts.
2. Loosen bolt, holding pump to mounting brackets,
release tension on drive belts.
3. Move belts out of the way, then remove pump
hoses, vacuum and electrical connections, and
control valve.
4. Pulley, then pump.
5. If required, insert needle nose pliers and pull filter
fan from hub.
Install or Connect
1. Air pump assembly, and tighten mounting bolts.
2. I-loses, vacuum and electrical connections, and
control valve
3. New
filter
fan on pump hub.
4. Spacer and pump pulley against centrifugal filter
fan.
5. Pump pulley bolts and tighten equally to 13 N m
(10 lb.
ft.). This will compress the centrifugal
filter fan onto the pump hole. Do not drive filter
fan on with a hammer. A slight amount of
interference with the housing bore is normal.
After a new filter fan has been installed, it
ma?;
squeal upon initial operation or until 0.11, sealing
lip has worn in. This
may require a short period of
purnp operation at various engine speeds.
6. Pump drive belt and adjust.
a Lon 7. Check air injection system for proper oper t'
(see CHART C-6)
AIR CONTROL VALVE
Remove or Disconnect
1. Battery ground cable.
2. Adapter bolts (See Figure C6-3).
3. Air outlet hoses from valve.
4. Adapter.
5. Electrical connectors and vacuum hoses from
valve. ve.
6. Control
va 1
Install or Connect
1. Control valve.
2. Electrical connectors and vacuum hoses.
3. Adapter.
4. Air hoses to valve.
5. Adapter bolts to pump.
6 Batterv ground crtble.
7. Check system operation (see CHART C-6)

TO MAF SENSOR
POWER & BURN-OFF
RELAY, OIL PRESS. SW.
.....-
439 PNKIBLK
419 BRNNVHT
SERIAL DATA
451 WHTIBLK
450
BLWHT
ALDL CONNECTOR
CHART A - 1
NO "'SERVICE ENGINE SOON" LIGHT
5.OL (VIN F) & 5.7L (VIN 8) "F'XSEBIE'S (PORT)
Circuit Description:
There should always be a steady "Service Engine Soon" light when the ignition is "ON" and engine stoppccl.
Ignition voltage is supplied directly to the light bulb. The electronic control module (ECM) will control the light
and turn it
"ON" by providing a ground path through CKT 419 to the ECM.
Test Description: Numbers below refer to circled
numbers on the diagnostic chart.
1. If the fuse in holder is blown, refer to facing page
of Code
54 for complete circuit.
2. Using a test light connected to 12 volts probe each
of the system ground circuits to be sure a good
ground is present. Refer to the ECM terminal end
view in front of this section for ECM pin locations
of ground circuits.
Diagnostic Aids:
Engine runs OK, check:
r Faulty light bulb.
@ CKrI' 419 open.
@ Gage fuse blown. This
will result in no oil or
generator lights, seat belt reminder, etc.
Engine cranks but will not run, check:
r Continuous battery - fuse or fusible link open.
@ ECM ignition fuse open.
r Battery CKT 340 to ECM open.
@ Ignition CKT 439 to ECM open.
@ Poor connection to ECM.

6E3-B-4 5.OL (VIN F) & 5.7L (VIN 8) DRIVEABILITY AND EMISSIONS
LACK OF POWER, SLUGGISH, OR SPONGY
Definition: Engine delivers less than expected power. Little or
no increase in speed when accelerator pedal is pushed down part way.
@ Perform careful visual check as described at
start of Section "B".
@ Compare customer's car to similar unit.
Make sure the customer's car has an actual
problem.
@ Remove air cleaner and check air filter for
dirt, or for being plugged. Replace as
necessary.
@ CHECK:
- For loose or leaking air duct between MAF
sensor and throttle body.
- Ignition timing. See emission control
information label.
- Restricted fuel filter, contaminated fuel or
improper fuel pressure. See CHART A-7.
- ECM Ground circuits - See ECM wiring
diagrams.
- EGR operation for being open, or partly open
all the time
- CHART C-7.
- Exhaust system for possible restriction: See
CHART
B-1.
- Inspect exhaust system for damaged or
collapsed pipes.
- Inspect muffler for heat distress or possible
internal failure.
- For possible plugged catalytic convertor by
comparing exhaust system backpressure on
each side at engine. Check backpressure by
removing
A.1.R check valves near exhaust
manifolds. See CHART
B-1 for procedure.
- Generator output voltage. Repair if less than 9
or more than 16 volts.
- Engine valve timing and compression.
- Engine for proper or worn camshaft. See Section
"6A".
- Secondary voltage using a shop ocilliscope or a
spark tester
5-26792 (ST-125) or equivalent.
- Check for excessive knock retard. See CHART
C-5.
DETONATION ISPARK KNOCK
Definition: A mild to severe ping, usually worse under
acceleration. The engine makes sharp metallic knocks that
change with throttle opening. Sounds like popcorn popping.
@ Check for obvious overheating problems:
- Low coolant.
- Loose water pump belt.
- Restricted air flow to radiator, or restricted
water flow thru radiator.
- Inoperative electric cooling fan circuit. See
CHART C-12.
@ CHECK:
- Ignition timing. See vehicle emission control
information label.
- EGR system for not opening - CHART C-7.
- TCC operation - CHART C-8.
- Fuel system pressure. See CHART A-7.
- Mem-Cal - Be sure it's the correct one. (See
"Service Bulletins").
- Valve oil seals for leaking.
@ Check for incorrect basic engine parts such as
cam, heads, pistons, etc.
@ Checkforpoorfuelquality.
@ Remove carbon with top engine cleaner. Follow
instructions on can.
@ Check ESC system
See CHART C-5
@ To help determine if the condition is caused by a
rich or lean system, the car should be driven at
the speed of the complaint. Monitoring block
learn at the complaint speed will help identify the
cause of the
problem. If the system is runnig lean
(block learn greater than
1381, refer to
"Diagnostic Aids" on facing page of Code
44. If
the system is running rich (block learn less than
1181, refer to "Diagnostic Aids" on facing page of
Code 45.

DRIVEABILITY AND EMISSIONS 5.OL (VIN F) & 5.7L (VIN 8) 6E3-C6-1
SECTION C6
AIR INJECTION REACTION (A.I.R.) SYSEEM
CONTENTS
GENERAL DESCRIPTION ............... C6-1
PURPOSE ....................... C6-1
OPERATION. ..................... C6-1
AIR CONTROL PEDES VALVE ......... C6-1
.... RESULTS OF INCORRECT OPERATION C6-2
DIAGNOSIS
........................ C6-2
OPERATIONAL CHECKS ............. C6-2
Air Pump ...................... C6-2
Hoses and Pipes ................. C6-3
GENERAL DESCRIPTION
PURPOSE
The A.I.R. system helps reduce hydrocarbon (HC),
carbon monoxide (CO), and oxides of nitrogen (NO,)
exhaust emissions. It also heats up the catalytic
converter quickly on engine start-up so conversion of
exhaust gases can occur sooner.
A dual bed converter is used. It consists of a three
way catalyst (which controls all three emissions) in
series with
a two way catalyst (which controls only HC
and
CO) both are in one housing. A pipe between the
two converters allows air to be injected into the second
(two way) converter to increase its efficiency to further
control HC and CO (Figure
C6-L).
As shown in Figure C6-1, air can be directed to:
@ A divert silencer.
@ Exhaust ports; or
@ Catalytic converter.
OPERATION
The system (Figure C6-1) includes:
@ An Air Pump
The air pump is driven by a belt on the front of
the engine and supplies the air to the system.
Intake air passes through a centrifugal filter fan
at the front of the pump; where foreign materials
are separated from the air by centrifugal force.
@ A Control Valve (PEDESl
Air flows from the pump through an ECM
controlled valve (called a PEDES valve) through
check valves to either the exhaust ports or the
converter.
@ Check Valves
The check valves prevent back flow of exhaust
into the pump in the event of
an exhaust backfire
or pump drive belt failure.
@ Necessary Plumbing
Check Valve .................... C6-3
ON-CAR SERVICE
.................... C6-3
DRIVEBELT ...................... C6-3
AIR INJECTION PUMP ............... C6-3
AIR INJECTION CONTROL
(PEDES) VALVE..
................ C6-3
AIRINJECTIONCHECKVALVE.. ....... C6-4
PARTS INFORMATION
................ C6-4
CLOSED LOOP FUEL CONTROL I
(2I ECM
1 REDUCING CATALYST
1 OXIDIZING CATALYST
1 0) SENSOR
1 CHECK VALVE
1 AIR PUMP
(BI PORT SOLENOID
( CONVERTER SOLENOID
llO) ELECTRICAL SIGNALS
FROM ECM
j BY-PASS AIR TO ATMOSPHERE
Figure C6-1 - A.I.R. System Operation
AIR CONTROL PEDES VALVE
Pressure operated electric divertleleclric air
switching (PEDES) valves are used on
these engines.
The diverting and switching functions are
electronically controlled by the
ECM,which grounds
to complete the circuit and energize the solenoid. Self-
generated pressure from the A.I.R. pump
is used to
operate the valve, which is completely independent of
manifold vacuum.

6E3-C6-2 5.OL (VIN F) & 5.7L (VIN 8) DRIVEABILITY AND EMISSIONS
Air enters the body of the valve from the pump.
Air pressure builds against the control valve and for:
@ Cold Mode - The port solenoid is energized
which in turn opens the port valve and allows
flow to the exhaust ports.
Warm Mode
- The port solenoid is de-
energized and the converter solenoid
energized which closes the port valve and
keeps the converter valve seated, thus forcing
flow past the converter valve and to the
converter.
@ Divert Mode - Both solenoids are de-energized
which opens the converter valve, allowing air
to take the path of least resistance,
i.e., out the
divertlrelief tube to atmosphere. Electrical
failure (open circuit) of the control valve
will divert air flow overboard at all times. Air will
flow to the converter at all times if an open circuit
occurs to the switching valve (converter solenoid).
DIAGNOSIS
The diagnosis of the AIR system is covered in
CHART C-6 at the end of this section.
OPERATIONAL CHECKS
Air Pump
The air pump is a positive displacement vane type
which is permanently lubricated and requires no
periodic maintenance.
llccelerate engine to approximately 1500 rpm's
and observe air flow from hose(s). If air flow increases
as engine is accelerated, pump is operating
satisfactorily. If air flow does not increase or is not
present, proceed as follows:
Inspect
I. For proper drive belt tension.
2. For a leaky pressure relief valve. Air may be
heard leaking with the pump running.
TO CONVERTER AIR INLET
TO EXHAUST PORTS
1 SOLENOID
Figure C6-2 - A.I.R. System Control Valve
Air is diverted to the atmosphere under the
lowing conditions:
Rich operation.
When the
ECM recognizes a problem and sets a
trouble code.
@ During deceleration.
During high rprn operation when air pressure is
greater than the setting
for the internal relief
valve.
RESULTS OF INCORRECT OPERATION
If no air (oxygen) flow enters the exhaust stream
at the exhaust ports, I-IC and CO emission levels will
be too high.
Air flowing to the exhaust ports at all times could
increase temperature of the converter.
Air flowing at all times to the catalytic converter
may cause converter overheating during rich
a ion.
oper
t'
Mechanical failures in the valves could cause the
air to flow incorrectly to the exhaust ports or the
converter.
NOTICE : If the engine or underhood compartment is
to be cleaned with steam or high-pressure
detergent, the centrifugal filter fan should
be masked off to prevent liquids from
entering the pump (see Figure
C6-3).
NOTICE: The AIR system is not completely
noiseless. Under normal conditions, noise
rises in pitch as engine speed increases.
To determine if excessive noise is the fault
of the air injection reactor system, operate
the engine with the pump drive belt
removed. If excessive noise does not exist
with the belt removed proceed as follows:
a inspect
3. For a seized air injection pump.
4. Hoses, tubes and all connections for leaks and
proper routing.
5. For air flow from control/switching valve.
6. AIR injection pump for proper mounting and bolt
torque.
7. If no irregularities exist and the AIR injection
pump noise is still excessive, remove and replace
Pump.
CAUTION: 110 Not Oil Pump

DRlVEABlLlfVAND EMISSIONS 5.OL (VIN F) & 5.7L (VIN 8) 6E3-C6-3
Hoses and Pipes
1. Hose or pipe for deterioration or holes.
2. All hoses or pipe connections, and clamp tightness.
3. Hose or pipe routing. Interference may cause
wear.
4. If
a leak is suspected on the pressure side of the
system or if a hose or pipe has been disconnected
on the pressure side, the connections should be
checked for leaks with a soapy water solution.
With the pump running, bubbles will form if a
leak exists.
Check Valve
Inspect
1. A check valve should be inspected whenever the
hose is disconnected from a check valve or
whenever check valve failure is suspected.
(A
pump that had become inoperative and had shown
indications of having exhaust gases in the pump
would indicate check valve failure).
2. Blow through the check valve (toward the cylinder
head) then attempt to suck back through the check
valve. Flow should only be in one
direction(toward the exhaust manifold). Replace
valve which does not operate properly.
ON-CAR SERVICE
DRIVE BELT
Remove or Disconnect
1. Inspect drive belt for wear, cracks or deterioration
and replace if required. When installing a new
belt, it must be seated and fully secured in grooves
of all belt driven components.
AIR INJECTION PUMP
Remove or Disconnect
1. Hold pump pulley from turning by cotnpressing
drive belt, then loosen pump pulley bolts.
2. Drive belt and pulley.
3. Hoses, vacuum, and electrical connections from
air injection control valve.
4. Air pump mounting bolts, and pump assembly
(See Figure
C6-3).
Install or Connect
3. Pump pulley bolts and tighten equally to 13 N.m
(10 lb. ft).
4. Check air injection system for proper operation
(see CHART C-6).
Figure C6-3 - Air Pump Service
AIR INJECTION CONTROL (PEDES) VALVE
Remove or Disconnect
1. Battery ground cable.
2. Adapter bolts (See Figure C6-4).
3. Air outlet hoses from valve.
4. Splash guardlcover
5. Electrical connectors and vacuum hoses from
valve.
6. Control valve.
Install or Connect
1. Control valve.
2. Electrical connectors.
3. Splash guard/cover.
4. Air hoses to valve.
5. Battery ground cable.
6. checksystem operation (see CHART C-6).
1. Air pump assembly, and tighten mounting bolts
2. Spacer and pump pulley against centrifugal lilter
fan.