Chevrolet 1963 Corvette, Руководство по ремонту и настройке, Страница: 54 / 346

TUNE-UP AND PERFORMANCE MAINTENANCE 49
CHECK ENGINE lamp location. This lamp will be illuminated while the EST BYPASS wire is disconnected
the distributor housing which join at a com-
mon multi-connector, close to the distribu-
tor. Follow the tan wire with a black stripe
(EST BYPASS wire) from the multi-connec-
tor. Past the multiconnector, the EST BY-
PASS wire has its own, single connector.
NOTE:
On 1984 models, disconnect the 4
terminal EST connector to operate in the
bypass timing mode.
Separate this connector before adjusting the
timing. While the EST BYPASS wire is dis-
connected, the CHECK ENGINE light on
the instrument panel will illuminate. After
adjusting the timing, reconnect the EST BY-
PASS connector; the CHECK ENGINE light
will go out.
NOTE: It is not necessary to adjust the idle
speed on 1982—84 models prior to the timing
adjustment, though the engine must be at
normal operating temperature. 1984
models incorporate an Electronic Spark
Control (ESC) into the distributor which
retards the spark advance when engine det-
onation occurs. If the controller fails, the re-
sult could be no ignition, no retard or full re-
tard. Some engines will also have a magnetic
timing probe hole for use with electronic tim-
ing equipment. Consult the manufacturer's
instructions for the use of this equipment.
Valve Lash
ADJUSTMENT
Engines equipped with hydraulic lifters
VERY rarely need adjustment of the valve
lash. If the vehicle runs well and there is no
audible "clicking" in the valvetrain, leave it
alone. This is because removal of the valve
covers on vehicles equipped with air condi-
tioning, various emission controls, cruise
control, etc., can be a major project in itself.
On air conditioned models, the A/C com-
pressor must be moved out of the way to gain
access to one of the valve covers. Do not dis-
connect the refrigerant lines to move the
compressor. After the cover is removed,
either move the compressor to retighten the
belt or remove the belt completely so that it
will not tangle while the engine is running.
On early models equipped with fuel injec-
tion, removal of the left valve cover requires
removal of the air cleaner hose, air meter
adaptor, and pyrometer housing.
If wiring is attached to metal clips on the
valve cover, carefully bend each clip to free
the wire from the valve cover. If corrugated
plastic tubing containing wiring is attached to
the valve cover with plastic clips, the clips
can be undone by gently twisting the upper