GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 639
In the HEI system, as in other electr
onic ignition systems, the breaker points
have been replaced wit h an electronic switch - a tr ansistor - which is located
within the ignition module. This switching transistor pe rforms the same function
the points did in a conventi onal ignition system; it simply turns the coil's primary
current on and off at the correct time. Essentially, electronic and conventional
ignition systems operate on t he same principle.
The module which houses the switching transistor is controlled (turned on and
off) by a magnetically gener ated impulse induced in the pickup coil. When the
teeth of the rotating timer align with t he teeth of the pole piece, the induced
voltage in the pickup coil signals the elec tronic module to open the coil primary
circuit. The primary current then decreases, and a high voltage is induced in the
ignition coil secondary windings, which is then directed through the rotor and
high voltage leads (spark plug wires) to fire the spark plugs.
In essence, the pickup coil module system simply replaces the conventional
breaker points and condenser. The condenser found within the distributor is for
radio suppression purposes only and has nothing to do with the ignition
process. The ignition module automatically controls the dwell period, increasing
it with increasing en gine speed. Since dwell is co ntrolled in this manner, it
cannot be adjusted. The module itse lf is non-adjustable/non-repairable and
must be replaced if found defective.
SYSTEM PRECAUTIONS
Before proceeding with troubleshooting, ta ke note of the following precautions:
TIMING LIGHT USE
Care should be exercised when connec ting a timing light or other pick-up
equipment. Do not force anything between the boots and wiring, or through the
silicone jacket. Connections should be made in parallel using an adapter.
Inductive pickup timing lights are the bes t kind to use with the ignition systems
covered by this information.
SPARK PLUG WIRES
The plug wires used with these systems are of a different construction than
conventional wires. When replacing them, make sure you get the correct wires,
since conventional wires will not carry the voltage. Also, handle the wires
carefully to avoid cracking or splitti ng them, and NEVER pierce the wires.
TACHOMETER USE
Not all tachometers will operate or indi cate correctly when used on an HEI or
C
3I system. While some tachometers ma y give a reading, this does not
necessarily mean the reading is correct. In addition, some tachometers hook up
differently from others. If you cannot fi gure out whether or not your tachometer
will work on your car, check with the tachometer manufacturer.
