GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 594
REMOVAL & INSTALLATION
1. Disconnect the negative battery cable.
2. Raise and safely support the vehicle.
3. Disconnect the VSS electrical wiring.
4. Remove the retaining bolt.
5. Have a clean container to catch the transmission fluid and remove the
VSS.
6. Remove and discard the O-ring.
To install: 7. Lubricate a new O-ring with a thin f ilm of transmission fluid. Install the O-
ring and VSS.
8. Install the retaining bolt.
9. Connect the electrical wiring.
10. Lower the vehicle.
11. Connect the negative battery cable.
12. Refill transmission to proper level.
TROUBLE CODES
SELF DIAGNOSTICS
READING CODES
The following procedure applies to mode ls with the 12 pin diagnostic connector
only.
1. Turn the ignition switch OFF. Locate the Assembly Line Diagnostic Link
(ALDL), usually under the instrument panel. It may be within a plastic
cover or housing labeled DIAGNOSTIC CONNECTOR. This link is used
to communicate with the ECM.
2. Use a small jumper wire to connect Terminal B of the ALDL to Terminal
A. As the ALDL connector is viewed from the front, Terminal A is on the
extreme right of the upper row; Terminal B is second from the right on
the upper row.
3. After the terminals are connected, turn the ignition switch to the ON
position but do not start the engine. T he dash warning lamp should begin
to flash Code 12. The code will disp lay as one flash, a pause and two
flashes. Code 12 is not a fault code. It is used as a system
acknowledgment or handshake code; its presence indicates that the
ECM can communicate as requested. Code 12 is used to begin every
diagnostic sequence.
4. After Code 12 has been transmitted 3 times, the fault codes, if any, will
each be flashed in the same manner th ree times. The codes are stored
and transmitted in numeric order from lowest to highest.
The order of codes in the memory does not indicate the order of occurrence.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 596
recommended to have a qualified technici
an perform any further testing, if
needed.
FIELD SERVICE MODE
On fuel injected models, if the ALDL terminal B is grounded to terminal A with
the engine running, the system enters the Field Service Mode. In this mode, the
MIL will indicate whether the system is operating in open loop or closed loop.
If working in open loop, t he MIL will flash rapidly 2
1/2 times per second. In
closed loop, the flash rate slows to once per second. Additionally, if the system
is running lean in closed loop, the lamp will be off most of the cycle. A rich
condition in closed loop will cause the lamp to remain lit for most of the one
second cycle.
When operating in the Field Service M ode, additional codes cannot be stored
by the ECM. The closed loop timer is bypassed in this mode.
CLEARING CODES
Stored fault codes may be erased from me mory at any time by removing power
from the ECM for at least 30 seconds. It may be necessary to clear stored
codes during diagnosis to check for any re currence during a test drive, but the
stored should be written dow n when retrieved. The codes may still be required
for subsequent troubleshooting. Whenever a repair is complete, the stored
codes must be erased and the vehicle te st driven to confirm correct operation
and repair.
The ignition switch must be OFF any ti me power is disconnected or restored to
the ECM. Severe damage may result if this precaution is not observed.
Depending on the electric di stribution of the particular vehicle, power to the
ECM may be disconnected by removing the ECM fuse in the fusebox or
disconnecting the inline EC M power lead at the positive battery terminal.
Disconnecting the negative battery cable to clear codes will achieve the desired
result, but this will also clear other me mory data in the vehicle such as radio
presets or seat memory.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 629
as much voltage to fire the plug at hi
gh speeds than at idle. The improved
air/fuel ratio control of modern fuel injection combin ed with the higher voltage
output of modern ignition systems will often allow an engine to run significantly
longer on a set of standard spark plugs, but keep in mind that efficiency will
drop as the gap widens (along wit h fuel economy and power).
When you're removing spark plugs, work on one at a time. Don't start by
removing the plug wires all at once, because, unless you number them, they
may become mixed up. Take a minute before you begin and number the wires
with tape.
1. Disconnect the negative battery cabl e, and if the vehicle has been run
recently, allow the engine to thoroughly cool.
2. Carefully twist the spark plug wire boot to loosen it, then pull upward and
remove the boot from the plug. Be su re to pull on the boot and not on the
wire, otherwise the connector locat ed inside the boot may become
separated.
3. Using compressed air, blow any water or debris from the spark plug well
to assure that no harmful contam inants are allowed to enter the
combustion chamber when the spark plug is removed. If compressed air
is not available, use a rag or a brush to clean the area.
Remove the spark plugs when the engine is cold, if possible, to prevent damage
to the threads. If removal of the plugs is difficult, apply a few drops of
penetrating oil or silicone spray to t he area around the base of the plug, and
allow it a few minutes to work.
4. Using a spark plug socket that is equipped with a rubber insert to
properly hold the plug, turn the spar k plug counterclockwise to loosen
and remove the spark pl ug from the bore.
WARNING - Be sure not to use a flexible extension on the socket. Use of a
flexible extension may allow a shear fo rce to be applied to the plug. A shear
force could break the plug off in the cylinder head, leading to costly a\
nd
frustrating repairs.
To install:
5. Inspect the spark plug boot for t ears or damage. If a damaged boot is
found, the spark plug wire must be replaced.
6. Using a wire feeler gauge, check and adjust the spark plug gap. When
using a gauge, the proper size shoul d pass between the electrodes with
a slight drag. The next larger size should not be able to pass while the\
next smaller size should pass freely.
7. Carefully thread the plug into the bor e by hand. If resistance is felt before
the plug is almost completely th readed, back the plug out and begin
threading again. In small, hard to r each areas, an old spark plug wire and
boot could be used as a th reading tool. The boot will hold the plug while
you twist the end of the wire and t he wire is supple enough to twist
before it would allow t he plug to crossthread.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 640
The tachometer terminal should never
be allowed to touch ground, as damage
to the computer control module and/or ignition coil assembly can result.
CONNECTORS
When disengaging connectors, do not use a screw driver or other tool to release
the locking tab, as this mi ght break the connector.
SYSTEM TESTERS
Instruments designed specific ally for testing HEI or C
3I systems are available
from several tool manufactur ers. Some of these will even test the module itself.
However, the tests given in the followin g section will require only an ohmmeter
and a voltmeter.
TESTING
The symptoms of a defective component within the HEI or C
3I system are
exactly the same as those you woul d encounter in a conventional system.
Some of these symptoms are:
• Hard or no starting
• Rough Idle
• Poor fuel economy
• Engine misses under load or while accelerating
PRELIMINARY CHECKS
If you suspect a problem in your igniti on system, there are certain preliminary
checks which you should carry out befor e you begin to check the electronic
portions of the system. First, it is extrem ely important to make sure the vehicle
battery is in a good state of charge. A defective or poorly charged battery will
cause the various components of the ignition system to read incorrectly when
they are being tested. Second, make su re all wiring connections are clean and
tight, not only at the battery, but also at the distributor cap (if so equipped),
ignition coil, camshaft and/or crankshaft sensors (if so equipped) and at the
control module.
Since the only difference between these ignition systems lies before the spark
plug wiring, it is important to check the secondary ig nition circuit first. If the
secondary circuit checks out properly (ther e is spark), then the engine condition
is probably not the fault of the ignition system. To check the secondary ignition
system, perform a simple spark test. Remove one of the plug wires and insert
some sort of extension in the plug socket. An old spark plug with the ground
electrode removed makes a good extension. Hold the wire and extension using
an insulated tool (NOT BY HAND) about
1/4 in. (6mm) away from the block and
crank the engine. If a normal spark occurs, then the problem is most likely not in
the ignition system. Check for fuel system problems, or fouled spark plugs.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 641
If, however, there is no spark or a weak
spark, then further ignition system
testing will have to be done. Troubleshooting techniques fall into various
categories, depending on t he nature of the problem and the system being
tested. Categories will include symptom s such as the engine cranks, but will not
start or the engine runs rough.
HEI SYSTEM
When testing the HEI system, there are 2 major categories of problems, (1)
Engine cranks, but will not star t or (2) Engine runs, but runs rough or cuts out.
If the engine will not start, perform a spar k test as described earlier. This will
narrow the problem area down considerab ly. If no spark occurs, check for the
presence of normal battery voltage at the battery ( BAT) terminal on the ignition
coil. The ignition switch must be in the ON position for this test. Either a
voltmeter or a test light wire may be us ed for this test. Connect the test light
wire to ground and the probe end to the BAT terminal at the coil. If the light
comes on, you have voltage to the distribut or and/or spark plug wires. If the light
fails to come on, this indicates an open circuit in the ignition primary wiring
leading to the distributor. In this case , you will have to check wiring continuity
back to the ignition switch using a test li ght. If there is battery voltage at the BAT
terminal, but no spark at the plugs, t hen the problem probably lies within the
distributor assembly.
If, on the other hand, the engine starts, but runs roughly or cuts out, make sure
the plug wires are in good shape first. There should be no obvious cracks or
breaks. You can check the plug wires with an ohmmeter, but do not pierce the
wires with a probe. Check the chart for th e correct plug wire resistance. If the
plug wires are OK, remove the cap asse mbly and check for moisture, cracks,
chips, or carbon tracks, or any other hi gh voltage leads or failures. Replace the
cap if any defects are found. Make su re the timer wheel rotates when the
engine is cranked.
If the trouble has been narrowed down to t he units within the distributor, the
following tests can help pinpoint the defective component. An ohmmeter with
both high and low ranges shou ld be used. These tests are made with the cap
assembly removed and the battery wir e disconnected. If a tachometer is
connected to the TACH terminal, disconnect it before making these tests.
IGNITION COIL
EXTERNALLY MOUNTED 1. Disconnect the coil wires and se t the ohmmeter on the high scale.
2. Connect the ohmmeter to the ignition co il as illustrated in Step 1 of the
accompanying figure.
3. The ohmmeter should read near infinite or very high.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 645
3. If no defects have been found at this
time, and you still have a problem,
then the module will have to be che cked. If you do not have access to a
module tester, the only possible alter native is a substitution test. If the
module fails the substitution test, replace it.
COMPONENT REPLACEMENT
CAUTION - When handling secondar y spark plug leads with the engine running
or starting, insulated pliers must be used and care exercised to prevent a
possible electrical shock.
HEI SYSTEM
IGNITION COIL
EXTERNALLY MOUNTED
1. Disconnect the negative battery cable.
2. Disconnect the ignition coil wire from the coil. Do so by pulling on the
boot of the wire while twisting it.
3. Disconnect the harness connecto r from the ignition coil.
4. Remove the coil mounting screws and the ignition coil. If necessary, drill
out and remove the rivets holding the coil to the bracket.
To install: 5. Place the ignition coil in position on the mounting bracket and install the
mounting screws.
6. Reconnect the harness connectors to the ignition coil. Confirm that the
harness connectors are firmly attached to the coil.
7. Install the secondary coil wire to the coil tower.
8. Connect the negative battery cable.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 648
INTERNALLY MOUNTED
1. Disconnect the negative battery cable.
2. Remove the cover and wire retainer.
3. Disconnect the battery feed wire and coil connections from the cap.
4. Remove the coil cover attaching screws and cover.
5. Remove the coil attaching screws and lift the coil assembly from the
distributor cap.
To install: 6. Position the ignition coil and the leads into the cap. Be certain that the
resistor brush, ground lead and s eal are properly positioned.
7. Install the mounting screws.
8. Install the coil cove r and retainers. Reconnec t the feed wires and coil
connections to the cap.
9. Install the cover and wire retainer. Reconnect the negative battery cable.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 651
Fig. 6: Removing the distri butor cap. Notice that all towers on cap are labeled
with the corresponding engine cylinder number.
ROTOR 1. Disconnect the negative battery cable.
2. Remove the distributor cap.
3. Unscrew the two rotor attaching screws and then lift off the rotor.
4. For installation, make sure the roto r is positioned in the correct direction
and tighten the retaining screws.
CAPACITOR
The capacitor, if equipped, is part of the ignition coil wire harness assembly.
Since the capacitor is used only for radio noise suppres sion, it will seldom need
replacement.
1. Disconnect the negative battery cable.
2. Remove the distributor cap and rotor.
3. Remove the capacitor attaching screws and unplug the connector from
the module. Remove the module.
To install: 4. Plug the connector into the capacitor. Install the capacitor and secure in
place using the mounting screws. Be sure the ground lead is under the
screw.
5. Install the rotor and distributor cap.