Idle Speed And Mixture Screws - Chevrolet 10 1971 Series Chassis Service Manual

CARBUR
(IDLE SP
SCREW
S O L E N O ID
SCR EW
Disconnect the distributor spark advance hose and
plug the vacuum source opening.
Adjust carburetor speed screw to obtain 600 rpm
with manual transmission in neutral and air condi­
tioning "OFF" ; 550 rpm with automatic transmission
in drive and air conditioning "ON" . DO NOT ADJUST
SOLENOID SCREW.
If the Combination Emission Control
CAU TIO N:
solenoid screw (fig. 17) is used to set engine
idle or if the solenoid is adjusted out of limits
as specified in Section 6M, a decrease in engine
braking may result.
Reconnect "Fuel Tank" line to vapor canister and
reconnect distributor spark advance hose.
• 350 Cu. In. (Four-Barrel Carburetor)
Disconnect "Fuel Tank" line from Evaporation
Emission vapor canister.
Disconnect the distributor spark advance hose and
plug the vacuum source opening.
Adjust carburetor speed screw to obtain 600 rpm
with manual transmission in neutral and air condi­
tioning "OFF" ; 550 rpm with automatic transmission
in drive and air conditioning "ON" . DO NOT ADJUST
SOLENOID SCREW.
If the Combination Emission Control
C AU TIO N :
solenoid screw (fig. 17) is used to set engine
idle or if the solenoid is adjusted out of limits
as specified in Section 6M, a decrease in engine
braking may result.
Place fast idle cam follower on second step of fast
idle cam, turn air conditioning "O FF" and adjust
fast idle to 1350 rpm with manual transmission in
neutral; 1500 rpm with automatic transmission in
"Park" .
* ROCHESTER M O N O J E T
(IDLE SPEED) SCREW
Fig. 17— Idle Speed and Mixture Screws
ROCHESTER 2 G V
SO LE N O ID
SCREW
ID
MIXTUR
CARBURETOR (IDLE
ROCHESTER 4 M V (Q U A D R A JE T )
Reconnect "Fuel Tank" line to vapor canister and
reconnect distributor spark advance hose.
• 402 Cu. In. (Four-Barrel Carburetor)
Disconnect "Fuel Tank" line from Evaporation
Emission vapor canister.
Disconnect the distributor spark advance hose and
plug the vacuum source opening.
Turn air conditioning "O FF" and adjust carburetor
speed screw to obtain 600 rpm with manual trans­
mission in neutral and automatic transmission in
"Drive" . DO NOT ADJUST SOLENOID SCREW.
If the Combination Emission Control
C AU TIO N :
solenoid screw (fig. 17) is used to set engine
idle or if the solenoid is adjusted out of limits
as specified in Section 6M, a decrease in engine
braking may result.
Place fast idle cam follower on second step of fast
idle cam, turn air conditioning "OFF" and adjust
fast idle to 1350 rpm with manual transmission in
neutral; 1500 rpm with automatic transmission in
" Park" .
Reconnect " Fuel Tank" line to vapor canister and
reconnect distributor spark advance hose.
10 Series Vehicles with Liquid Petroleum Gas (LPG) Engines
1. With engine running at operating temperature, choke
valve in fully open position, parking brake on and
drive wheels blocked - adjust idle speed as follows
(See "Tune-Up" Decal Figure 18):
All carburetors are equipped with idle
NOTE:
mixture limiter caps (fig. 17); the idle mixture
is preset and "locked in" by these caps - no
attempt should be made to adjust mixture. Do
not remove mixture screw caps.
ENGINE 6-9
S O L E N O ID
SPEED) SCREW
10-30 CHEVROLET TRUCK SERVICE MANU.