Chevrolet CHEVY VAN G10 SERIES Service Manual page 180

ENGINE FUEL 6M-6
Fig. 15C —C .E .C . V alve A d ju s tm e n t
C.E.C. V A L V E ADJUSTMENT
(L-6 ENGINES)
(EXCEPT 30 SERIES, CARGO VANS)
IM P O R T A N T : Do not set CEC Valve adjustment to
idle R.P.M . The CEC
specified R.P.IVI. See Section 6M , Specifications,
under "O th e r Adjustm ents."
C A U T IO N : If 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 adjustm ent is to be m ade only after, (1) replacem ent
2
o f th e solenoid, ( ) m ajor overhaul o f the carburetor is
perform ed, or (3) after the th ro ttle body is rem oved and
replaced.
The C.E.C. valve setting is made only after com pleting
in stru ction on tune-up sticker.
With engine running and transm ission in " N eu tral" for
m anual, and in " Drive" for autom atics, w ith air conditioning
off, d istributor vacuum hose removed and plugged, and fuel
tan k hose from vapor canister disconnected, perform the
following:
Fig. 16C —A ir Valve Dashpot A djustm ent (4 M V )
(Solenoid) Valve has a
Fig. 17C —A c c e le ra to r Pum p R o d A d ju s tm e n t (2 G V )
1. M anually extend the C.E.C. valve plunger to contact
th ro ttle lever.
2. A djust plunger length to obtain C.E.C. valve R.P.M. (see
" O ther A djustm ents" in Specifications at end o f this
m anual — Colum n No. 3).
3. R econnect fuel tank vapor hoses to the canister and
d istrib u to r vacuum hoses.
AIR V A L V E DASHPOT ADJUSTMENT
4M V (Fig. 16C)
1. C om pletely seat choke vacuum break diaphragm using an
outside vacuum source.
2. With choke diaphragm seated and air valve fully closed,
measure the distance betw een the end o f slot in vacuum
break plunger lever and air valve.
ACCELERATOR PUMP ROD ADJUSTMENT
2GV (Fig. 17C)
Back o u t idle stop screw and com pletely close th ro ttle
valves in bore. Place gauge on to p of air horn ring. Bend the
pum p rod at lower angle to obtain.
C H E V Y V A N S H O P M A N U A L