Chevrolet CHEVY VAN G10 SERIES Service Manual page 195

COMPONENT DESCRIPTION
Idle Stop Solenoid
The idle stop solenoid is a tw o position electrically oper­
ated con trol, used to provide a predeterm ined th ro ttle setting
(Fig. 6T-5). In the energized position (plunger extended) the
plunger contacts th e carburetor th ro ttle lever and prevents full
closing o f th e carb uretor th ro ttle plates. This fast idle control
w hen de-energized (plunger retracted) allows th ro ttle plates to
close b eyond the norm al idle position; thereby shutting o ff air
supply and in essence starving the engine so th a t it will shut
dow n w ithout dieseling. T he idle stop solenoid is bracket-
attached to the carburetor so th a t the plunger, w hen extended,
contacts the th ro ttle lever.
CEC Solenoid
T he CEC solenoid (Fig. 6T-5) is a tw o-position electrically
o perated control, w hich serves a dual function in the TCS
system . In the de-energized position the spring loaded plunger
closes the vacuum supply p o rt to th e distrib uto r advance unit
and opens the air vent to th e advance u nit. In the energized
position the plunger is extend ed to contact the carburetor
th ro ttle lever and to open the vacuum p o rt to the distributor
and to shut o ff the air vent. The solenoid is bracket-attached
to the carburetor so th a t the plunger, w hen extended, contacts
the th ro ttle lever to m aintain a predeterm ined engine RPM.
Time Relay
T he tim e relay is an electrically o perated on-off type
sw itch. When the coil is energized it begins to heat the bi-metal
strip to open the norm ally closed relay points in ap proxi­
m ately 20 seconds. A ground p ath is provided for through the
Fig. 6 T -5 — L-6 Idle Stop & CEC Solenoids
EMISSION CO N TR O L SYSTEM 6T-3
TCS TEMPERATURE SWITCH
Fig. 6 T -6 —L-6 Tem perature Cold Override Switch
relay h o u sin g a n d m o u n tin g b rac k et.
screw s a ttac h th e relay to the v ertical w all of th e cow l
b elow th e b ra k e m a in cylinder.
Temperature Cold Override Switch
The cold override sw itch, located in th e th erm o stat housing
6 6
(Fig. T- ) serves to activate th e CEC solenoid. At coolant
tem peratures below 82 (± 7 ) degrees, th e cold term inal is
contacted by the bi-m etallic strip to ground and com pletes the
circuit to th e CEC solenoid. In th e neutral position, no contact
is m ade; therefore the circuit is broken.
Transmission Switch
On m anual shift synchrom esh transm issions, b o th 3- and
4-speed, the sw itch is located on the outside o f the trans­
mission case in an area adjacent to the 2-3 or 3-4 shifter shaft,
as applicable (Fig. 6T-7). T he mechanically operated sw itch is
spring loaded to provide co n tin u ity betw een the switch ter-
Fig. 6 T -7 —Transmission Switch Location (Manuall
T w o self-tap p in g
C H E V Y V A N SH O P M A N U A L