1982 CHEVROLET CAMARO air conditioning

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 465

Fig. 12: Muffler hanger attachment
ENGINE RECONDITIONING DETE RMINING ENGINE CONDITION
Anything that generates heat and/or friction will eventually burn or wear out (i.e.
a light bulb generates heat, therefore its life span is limited). With this in mind, a
running engine generates trem endous amounts of both; friction is encountered
by the moving and rotating parts inside the engine and heat is created b\
y
friction and combustion of the fuel. Ho wever, the engine has systems designed
to help reduce the effects of heat and fr iction and provide added longevity. The
oiling system reduces the amount of fr iction encountered by the moving parts
inside the engine, while the cooling system reduces heat created by friction and
combustion. If either system is not main tained, a break-down will be inevitable.
Therefore, you can see how regular main tenance can affect the service life of
your vehicle. If you do not drain, flush and refill your cooling system at the
proper intervals, deposits will begin to accumulate in the radiator, thereby
reducing the amount of heat it can extrac t from the coolant. The same applies to
your oil and filter; if it is not changed often enoug h it becomes laden with
contaminates and is unable to properly lubricate the engine. This increases
friction and wear.
There are a number of methods for evaluat ing the condition of your engine. A
compression test can reveal the condition of your pistons, piston rings, cylinder
bores, head gasket(s), valves and valve seat s. An oil pressure test can warn
you of possible engine bearing, or oil pump failures. Excessive oil consumption,
evidence of oil in the engine air intake area and/or bluish smoke from the tail
pipe may indicate worn piston rings, worn valve guides and/or valve seals. As a
general rule, an engine that uses no more than one quart of oil every 1000
miles is in good condi tion. Engines that use one quart of oil or more in less than
1000 miles should first be checked for oil leaks. If any oil leaks are present,
have them fixed before dete rmining how much oil is consumed by the engine,
especially if blue smoke is not visible at the tail pipe.
COMPRESSION TEST
A noticeable lack of engine power, excessive oil consumption and/or poor fuel
mileage measured over an extended period are all indicators of internal engine

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 581

Fig. 1: Coolant temperature sensor. The in take air temperature sensor is similar
in appearance
IDLE AIR CONTROL (IAC) VALVE
OPERATION
Engine idle speeds are controlled by the ECM through the IAC valve mounted
on the throttle body. The ECM sends volt age pulses to the IAC motor windings
causing the IAC motor shaft and pintle to move IN or OUT a given distance
(number of steps) for each pulse (called counts). The movement of the pintle
controls the airflow around the throttle plat e, which in turn, controls engine idle
speed. IAC valve pintle position counts ca n be observed using a scan tool. Zero
counts correspond to a fully closed passage, while 140 counts or more
corresponds to full flow.
Idle speed can be categorized in 2 ways : actual (controlled) idle speed and
minimum idle speed. Contro lled idle speed is obtained by the ECM positioning
the IAC valve pintle. Resulting idle speed is determined by total air fl\
ow
(IAC/passage + PCV + throttle valve + ca librated vacuum leaks). Controlled idle
speed is specified at normal operating c onditions, which consists of engine
coolant at normal operating temper ature, air conditioning compressor OFF,
manual transmission in neutral or automatic transmission in D.
Minimum idle air speed is set at t he factory with a stop screw. This setting
allows a certain amount of air to bypas s the throttle valves regardless of IAC
valve pintle positioning. A co mbination of this air flow and IAC pintle positioning
allows the ECM to control engine idle speed. During normal engine idle
operation, the IAC valve pintle is positioned a calibrated number of steps
(counts) from the seat. No adjustment is required during routine maintenance.
Tampering with the minimum idle speed adjustment may result in premature
failure of the IAC valve or imprope rly controlled engine idle operation.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 659
VALVE LASH

All models utilize a hydraulic valve lifter system to obtain zero lash. No periodic
adjustment is necessary. An initial adjustm
ent is required anytime that the lifters
are removed or the valve tr ain is disturbed. This procedure is covered in Engine
& Engine Overhaul .

IDLE SPEED AND MIXTURE ADJUSTMENTS

Mixture adjustments are factory set and sealed; no adjustment attempt should
be made, except by an aut horized GM dealer or reputable shop equipped with
the necessary equipment.

IDLE SPEED
2-BBL CARBURETOR
WITHOUT AIR CONDITIONING
The engine must be running in "Closed Loop" mode (engine fully warmed) when
making all idle speed adjustments. In this mode, the oxygen sensor affects
control of the fuel delivery.
1. Refer to the emission label on the vehicle and prepare the engine for
adjustments (set the timing). Remove the air cleaner and set the parking
brake. Connect a tachometer to the distributor connector.
2. Place the transmission in DRIVE for automatic transmission, or
NEUTRAL for manual transmission; make sure that the solenoid is
energized.
3. Open the throttle slightly to allow the solenoid plunger to extend. Adjust
the curb idle speed to the specified rpm by turning the solenoid screw.
4. De-energize the solenoid by disconnecting the electrical lead.
5. Set the basic idle speed rpm by turning the idle speed screw. After
adjustment, reconnect the solenoid electrical lead.
6. Remove the tachometer and install the air cleaner.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 660

Fig. 1: Idle speed adjustm ents - 2-bbl carburetor (without air conditioning)
WITH AIR CONDITIONING
The engine must be running in "Closed Loop" mode (engine fully warmed) when
making all idle speed adjustments. In this mode, the oxygen sensor affects
control of the fuel delivery.
1. Refer to the emission label on the vehicle and prepare the engine for
adjustments (set the timing). Remove the air cleaner and set the parking
brake. Connect a tachometer to the distributor connector.
2. Place the transmission in DRIVE for automatic transmission, or
NEUTRAL for manual transmission. Tu rn the air conditioning OFF and
set the curb idle speed by turning the idle speed screw.
3. Disconnect the electrical lead at the A/C compressor, then turn the A/C
switch ON.
4. With the solenoid e nergized, open the throttle slightly to allow the
solenoid plunger to extend.
5. Turn the solenoid screw to adjust to the specified rpm. After adjustment,
reconnect the A/C compressor lead and turn the air conditioning OFF.
6. Remove the tachometer and install the air cleaner.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 661

Fig. 2: Idle speed adjustm ents - 2-bbl carburetor (with air conditioning)
4-BBL CARBURETOR
WITHOUT AIR CONDITIONING
The engine must be running in "Closed Loop" mode (engine fully warmed) when
making all idle speed adjustments. In this mode, the oxygen sensor affects
control of the fuel delivery.
1. Refer to the emission label on the vehicle and prepare the engine for
adjustments (set the timing). Se t the parking brake. Connect a
tachometer to the dist ributor connector.
2. Place the transmission in DRIVE for automatic transmission, or
NEUTRAL for manual transmission.
3. De-energize the idle speed solenoid by disconnecting the electrical lead.
4. Set the basic idle speed rpm by turning the idle speed screw.
5. Connect a jumper wire from a 12-vo lt power supply to the solenoid.
6. Open the throttle partially to ensure that the solenoid plunger is fully
extended, and allow the throttle lever to close on the plunger.
7. Turn the solenoid plunger to adj ust to the specified rpm. After
adjustment, disconnect the jumper wire and reconnect the solenoid
electrical lead.
8. Remove the tachometer and install the air cleaner.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 662

Fig. 3: Idle speed adjustm ents - 4-bbl carburetor
WITH AIR CONDITIONING
The engine must be running in "Closed Loop" mode (engine fully warmed) when
making all idle speed adjustments. In this mode, the oxygen sensor affects
control of the fuel delivery.
1. Refer to the emission label on the vehicle and prepare the engine for
adjustments (set the timing). Se t the parking brake. Connect a
tachometer to the dist ributor connector.
2. Place the transmission in DRIVE for automatic transmission, or
NEUTRAL for manual transmission. Tu rn the air conditioning OFF.
3. De-energize the idle speed solenoid by disconnecting the electrical lead.
4. Set the basic idle speed rpm by turning the idle speed screw. After
adjustment, reconnect the solenoid electrical lead.
5. Disconnect the electrical lead from the A/C compressor and turn the A/C
switch ON.
6. Open the throttle partially to ensure that the solenoid plunger is fully
extended, and allow the throttle lever to close on the plunger.
7. Turn the solenoid plunger to adj ust to the specified rpm. After
adjustment, reconnect the A/C co mpressor lead and turn the air
conditioning OFF.
8. Remove the tachometer and install the air cleaner.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 698
5. Disconnect and plug hose to canister purge port.
6. Disconnect and plug hose to idle load compensator.
7. Back out idle stop screw
on carburetor 3 turns.
8. Turn air conditioning OFF.
9. Block drive wheels, set parki ng brake, place transmission in P, start and
warm engine to normal operating temperature. Make certain choke is
OPEN .
10. With engine RUNNING place transmission in D and idle load
compensator fully extended (no vacuum applied). Using tool J-29607, or
equivalent, adjust plunger to obtain 650-750 rpm. Locknut on plunger
must be held with a wrench to prevent damage to guide tabs.
11. Measure distance from the locknut to tip of the plunger. This distance
must not exceed 1 in. (25mm). If it does check for low idle condition.
12. Reconnect vacuum hose to idle load compensator and observe idle
speed.
13. Idle speed should be between 425-475 rpm in D.
14. If idle speed is correct no further adjustment is necessary, proceed to the
next step. If idle speed is still incorrect continue as follows:
It may be necessary to remove the idle load compensator from the engine
unless a hex key wrench is m odified to clear obstructions.
a. Stop engine, remove rubber cap from the center outlet tube.
b. Using a 0.90 in. (23mm) hex wrench, insert through open center tube to
engage idle speed adjusting screw.
c. If idle speed was low, turn t he adjusting screw counterclockwise
approximately 1 turn for every 85 rpm low. If idle speed was high turn
screw 1 turn for every 85 rpm high.
15. Disconnect and plug vacuum hose to the idle load compensator.
16. Using a hand pump, apply vacuum to the idle load compensator until fully
retracted.
17. Adjust the idle stop screw on carburetor float bowl to obtain 450 rpm in
D .
18. Place transmission in P and stop engine.
19. Reconnect the idle load compensator.
20. Reconnect all vacuum hoses.
21. Install air cleaner and gasket. Remove wheel blocks.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 735

Fig. 2: IAC valve installation
MULTI-PORT FUEL INJECTION SYSTEMS

SYSTEM DESCRIPTIONS
The Multi-Port Fuel Injection (MPFI or MFI) systems were first introduced on the
1985 models. They may be called different names (Port Fuel Injection-PFI,
Tuned Port Injection-TPI, Sequential Fuel Injection-SFI), however, all of the
systems are similar in operation.
The systems are controlled by an Elec tronic Control Module (ECM) which
monitors the engine operations and gen erates output signals to provide the
correct air/fuel mixture, ignition timing and idle speed. Input information to the
ECM is provided by the oxygen sens or, temperature sensors, detonation
sensor, mass air flow sensor and throttle position sensor. A system may use all
or some of these sensors, depending on the year and engine application. The
ECM also receives information concerning engine rpm, road speed,
transmission gear position, power steer ing and air conditioning status.
All of the systems use multiple injector s, aimed at the intake valve at each
intake port, rather than the centrally lo cated injector(s) found on the earlier
Throttle Body Injection (TBI) and Crossfir e Injection systems. The injectors are
mounted on a fuel rail and ar e activated by a signal from the electronic control
module. The injector is a solenoi d-operated valve which remains open
depending on the width of t he electronic pulses (length of the signal) from the
ECM; the longer the open time, the more f uel is injected. In this manner, the
air/fuel mixture can be precisely c ontrolled for maximum performance with
minimum emissions.
There are two different types of f uel management systems used on the multi-
port fuel injection engines. The mass air flow system and the speed density
system.