Chevrolet 1963 Corvette, Руководство по ремонту и настройке

Страница: 66 / 346

ENGINE AND ENGINE REBUILDING 61
nition coil (though the ignition coils DO NOT
interchange), but is controlled by the timer
core, pole piece, and module; instead of the
breaker points and condenser.
NOTE: H.E.I, ignitions use a condensor,
but it is primarily used for radio interfer-
ence purposes.
As far as the mechanical advance is con-
cerned, the operation is also basically the
same as a conventional ignition system, with
the exception that the timer core rotates on
the distributor shaft instead of the distributor
cam used in conventional systems. The vac-
uum advance unit moves the breaker plate in
the same manner as the conventional system,
but the timing changes according to the po-
sition of the pole piece instead of the breaker
points.
Appearance wise, the transistorized igni-
tion distributor looks very much like a con-
ventional distributor, with the exception of a
two-wire lead (with a quick-disconnect plug)
coming from the dsitributor. Also, the tran-
sistorized system uses both an externally
mounted ignition coil and an ignition ampli-
fier unit which is finned for heat dissipation.
CAUTION: Do not use a conventional ig-
nition coil in place of an electronic ignition
coil, or vice-versa. Component damage
could result.
The H.E.I, distributor looks nothing like a
conventional distributor. The components of
an H.E.I, distributor are all contained within
the distributor (pole piece, ignition coil,
module, etc.).
Refer to Chapter 11 for detailed H.E.I,
system troubleshooting. None of the electri-
cal components used in either the transistor-
ized or H.E.I, systems are adjustable. If a
component is found to be defective, it must
be replaced.
HE/ SYSTEM PRECAUTIONS
Before going on to troubleshooting, it might
be a good idea to take note of the following
precautions:
Timing Light Use
Inductive pick-up timing lights are the best
kind to use if your car is equipped with HEI.
Timing lights which connect between the
spark plug and the spark plug wire occasion-
ally (not always) give false readings.
Spark Plug Wires
The plug wires used with H.E.I, systems are
of a different construction than conventional
wires. When replacing them, make sure you
get the correct wires, since conventional wires
won't carry the voltage. Also, handle them
carefully to avoid cracking or splitting them
and
never pierce them.
Tachometer Use
Not all tachometers will operate or indicate
correctly when used on a H.E.I, system.
While some tachometers may give a reading,
this does not necessarily mean the reading is
correct. In addition, some tachometers hook
up differently from others. If you can't figure
out whether or not your tachometer will work
on your car, check with the tachometer man-
ufacturer. Dwell readings, of course, have no
significance at all.
H.E.I. System Testers
Instruments designed specifically for testing
H.E.I, systems are available from several tool
manufacturers. Some of these will even test
the module itself. However, the tests given
in the following section will require only an
ohmmeter and a voltmeter.
ENGINE ELECTRICAL
Distributor
REMOVAL
Conventional and Transistorized Systems
1. Rotate the engine until the timing mark
on the crankshaft balancer is aligned with the
top dead center mark (TDC or "0") on the
timing tab scale. Remove the air cleaner as
sembly.
2. Remove the ignition shielding and dis
connect the secondary (high tension) coil wire.
3. Release the distributor cap hold-down
screws (push down and turn counterclock
wise). Raise the distributor cap off of the dis
tributor and check that the firing tip of the
rotor is pointed at the #1 terminal of the dis
tributor cap. If it is not; turn the engine one
full revolution and again align the timing
marks as previously stated. Recheck the rotor
position.
4. Pull the plug wires out of the locating
looms (if so equipped) and move the cap out
of the way. Leave the plug wires attached to
the cap.
5. Disconnect the battery cables at the
battery.
6. Disconnect the tachometer and fuel