Chevrolet Light Duty Truck 1973, Service Manual

Page: 445 / 979

E N G IN E FUEL 6 M -2 1
5. Install choke coil spring cover.
6
. Insert coil rod into choke coil lever slot and install
retaining clip.
7. Make sure that the choke valve operates freely and
coil rod does not bind on choke cover from the full
open to full closed position.
C.E.C. VALVE ADJUSTMENT
(L-6 ENGINES-EXCEPT H /D VEHICLES)
IM PORTANT:
Do not set CEC Valve adjust­
ment to idle R.P.M. The CEC (Solenoid)
Valve has a specified R.P.M. See Section
6
M,
Specifications, under "Other Adjustments."
CAUTIO N:
I f the CEC solenoid on the
carburetor is used to set the engine idle or is
adjusted out of limits specified in the Service
Manual, decrease in engine braking may result.
This adjustment is to be made only after, (1)
replacement of the solenoid, (
2
) major overhaul of the
carburetor is performed, or (3) after the throttle body is
removed and replaced.
The C.E.C. valve setting is made only after completing
instruction on tune-up sticker.
With engine running and transmission in "Neutral" for
manual, and "Drive" for automatics, with air condition­
ing off, distributor vacuum hose removed and plugged,
and fuel tank hose from vapor canister disconnected,
perform the following:
1. Manually extend the C.E.C. valve plunger to contact
throttle lever.
2. Adjust plunger length to obtain C.E.C. valve R.P.M.
(see "Other Adjustments" in Specifications at end
of this manual — Column No. 3).
3. Reconnect fuel tank vapor hoses to the canister and
distributor vacuum hoses.
AIR VALVE DASHPOT ADJUSTMENT 4MV
(Fig. 16C)
1. Completely seat choke vacuum break diaphragm
using an outside vacuum source.
2. With choke diaphragm seated and air valve fully
closed, measure the distance between the end of slot
in vacuum break plunger lever and air valve.
LIGHT DUTY TRUCK SERVICE MANUAL