1982 CHEVROLET CAMARO Repair Guide

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 569

Fig. 7: AIR system control valv e assembly; all models similar
EARLY FUEL EVAPORATION (EFE)
OPERATION
The EFE system is used on some of the engines to provide a source of rapid
engine heat up during cold operations. It hel ps reduce the time that carburetor
choking is required and helps reduce exhaust emissions.
There are two types of EF E systems. The vacuum servo type, consists of a
valve located in the exhaust manifold , an actuator and a Thermal Vacuum

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 570
Switch (TVS). The electrical type, cons
ists of a ceramic grid located under the
base of the carburetor.
A check of the operation should be made at regular maintenance intervals.
TESTING
VACUUM SERVO TYPE 1. With the engine cold, observe the posit ion of the actuator arm. Start the
engine. The arm should move toward the diaphragm (closing the valve).
2. If the arm does not move, remove the hose and check for vacuum. If still
no vacuum, remove the top hose from the TVS switch and check for
vacuum.
3. If vacuum is present in the top hose, replace the TVS switch.
4. If vacuum is present at the actuator and it does not move, try to free the
valve. If the valve cannot be freed, it must be replaced.
ELECTRICAL TYPE 1. Turn the ignition ON with the engine co ld and probe both terminals of the
heater switch connector with a test light.
• If 1 wire has power, replace the heater switch.
• If neither wire has power, repai r the ignition circuit.
• If both wires have power, probe the pink wire at the heater
connector (if no power, repair the c onnector of the heater switch).
2. If power exists at the pink wire , disconnect the heater connector and
connect a tester across the harness terminal. If no power, repair the
ground wire; if power exists, check the resistance of the heater.
3. If heater is over 3 ohm s, replace the heater. If under 3 ohms, replace the
connector, start the engine (operate to normal temperature) and probe
the pink wire. If no power, the system is OK; if power exists, replace the
heater switch.
REMOVAL & INSTALLATION
VACUUM SERVO TYPE 1. Disconnect the vacuum hose at the EFE.
2. Remove exhaust pipe to manifold nuts.
3. Remove the crossover pipe. Complete removal is not always necessary.
4. Remove the EFE valve.
To install: 5. Position the EFE valve into place.
6. Install the crossover pipe.
7. Install the exhaust pi pe to manifold nuts.
8. Connect the vacuum hose at the EFE.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 571

Fig. 1: Exploded view of a vacuum servo EFE valve assembly
ELECTRICAL TYPE 1. Remove the air cleaner and disconnect the negative battery cable.
2. Tag, then disengage all electrical, vacuum and fuel connections from the
carburetor.
3. Disconnect the EFE heat er electrical lead.
4. Remove the carburetor.
5. Lift off the EFE heater grid.
To install: 6. Position the EFE heater grid onto the manifold.
7. Install the carburetor.
8. Connect the EFE heater electrical lead.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 572
9. Connect all electrical, vacuum and f
uel connection to the carburetor.
10. Install the air cleaner and connec t the negative battery cable.

Fig. 2: Electric EFE heater assembly
ELECTRIC EFE RELAY 1. Disconnect the negative battery cable.
2. Remove the retaining bracket.
3. Tag and disconnect all el ectrical connections.
4. Unscrew the retaining bolts and remove the relay.
To install: 5. Position the relay into place and secu re the relay with the retaining bolt.
6. Attach all electrical connections.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 573
7. Install the retaining bracket.
8. Connect the negative battery cable.
ELECTRONIC ENGINE CONTROLS

COMPUTER COMMAND CO NTROL (CCC) SYSTEM
The Computer Command Control (CCC) Sy stem is an electronically controlled
exhaust emission system that can m onitor and control a large number of
interrelated emission cont rol systems. It can monitor various engine/vehicle
operating conditions and then use this in formation to control multiple engine
related systems. The CCC syst em is thereby making constant adjustments to
maintain optimum vehicle performance und er all normal driving conditions while
at the same time allowing the catalyti c converter to effectively control the
emissions of HC, CO and NO
x.
OPERATION
The Electronic Control Module (ECM) is required to maintain the exhaust
emissions at acceptable le vels. The module is a sma ll, solid state computer
which receives signals from many source s and sensors; it uses these data to
make judgements about operating conditions and then control output signals to
the fuel and emission systems to ma tch the current requirements.
Inputs are received from m any sources to form a complete picture of engine
operating conditions. Some inputs are simp ly Yes or No messages, such as that
from the Park/Neutral switch; the vehicle is either in gear or in Park/Neutral;
there are no other choices. Other data is sent in quantitative input, such as
engine rpm or coolant temperature. T he ECM is pre-programmed to recognize
acceptable ranges or combinations of si gnals and control the outputs to control
emissions while providing good driv eability and economy. The ECM also
monitors some output circuits, making sure that the components function as
commanded. For proper engine oper ation, it is essential that all input and output
components function properly and comm unicate properly with the ECM.
Since the control module is programmed to recognize the presence and value
of electrical inputs, it will also note the lack of a signal or a radical change in
values. It will, for example, react to the loss of signal from the vehicle speed
sensor or note that engine coolant temperature has risen beyond acceptable
(programmed) limits. Once a fault is recognized, a numeric code is assigned
and held in memory. The SERVICE ENGIN E SOON Malfunction Indicator Lamp
(MIL), will illuminate to advise the operator that the system has detected a fault.
More than one code may be stored. Although not every engine uses every
code, possible codes range from 12-999. Additionally, the same code may carry
different meanings relative to each engine or engine family. For example, on the
3.3L (VIN N) engine, code 46 indicates a fault found in the power steering
pressure switch circuit. The same code on the 5.7L (VIN F) engine indicates a
fault in the VATS anti-theft system.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 574
In the event of an ECM failure, the system
will default to a pre-programmed set
of values. These are compromise values which allow the engine to operate,
although possibly at reduced e fficiency. This is variously known as the default,
limp-in/limp-home or back-up mode. Driveability is almost always affected when
the ECM enters this mode.

Fig. 1: Computer Co mmand Control schematic

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 575

Fig. 2: Electronic Control Module (ECM)
LEARNING ABILITY
The ECM can compensate for minor variations within the fuel system through
the block learn and fuel in tegrator systems. The fuel integrator monitors the
oxygen sensor output voltage, adding or subtracting fuel to drive the mixture
rich or lean as needed to reach the ideal air fuel ratio of 14.7:1. The integrator
values may be read with a scan tool; the display will range from 0-255 and
should center on 128 if the oxygen sens or is indicating a 14.7:1 mixture.

Fig. 3: Among other features, a scan tool combines many standard testers into
a single device for quick and accurate diagnosis

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 576
The temporary nature
of the integrator's control is expanded by the block learn
function. The name is derived from the fact that the entire engine operating
range (load vs. rpm) is divided into sect ions or blocks. Within each memory
block is stored the correct fuel delivery value for that combination of load and
engine speed. Once the operating range enters a certain block, that stored
value controls the fuel delivery unless th e integrator steps in to change it. If
changes are made by the integrator, t he new value is memorized and stored
within the block. As the block learn makes the correction, the integrator
correction will be reduced until the integrator returns to 128; the block learn then
controls the fuel delivery with the new value.

Fig. 4: Inexpensive scan tools, such as this Auto Xray®, are available to
interface with your General Motors vehicle
The next time the engine operates within the block's range, the new value will
be used. The block learn data can also be read by a scan tool; the range is the
same as the integrator and should also center on 128. In this way, the systems
can compensate for engine wear, small air or vacuum leaks or reduced
combustion.
Any time the battery is disconnected, the block learn values are lost and must
be relearned by the ECM. This loss of corrected values may be noticed as a
significant change in driveab ility. To re-teach the system, make certain the
engine is fully warmed up. Drive the v ehicle at part throttle using moderate
acceleration and idle until normal performance is felt.