Carb (Slow) Idle Speed Adjustment; Idle Mixture Adjustment; Fast Idle Speed Adjustment; Choke Mechanism Service - Jeep J-10 Series 1982 Technical & Service Manual

/)•&&&&
• Do not idle the engine more than three minutes at a
time.
• If the mixture adjustment procedure requires more
than three minutes, operate the engine at 2000 rpm
for one minute.
• Ensure the ignition timing is correct before adjust
ing idle speed.
•Use extreme caution around fan, belts and other
moving parts when the engine is operating. Do not
wear loose clothing. Do not stand in direct line with
the fan blades.
Carb (Slow) Idle Speed Adjustment
(1) Disconnect and plug purge vacuum hose at va
por canister.
NOTE: Use a tachometer with an expandedscale ofUOQ
to 800 orOto 1000 rpm. Inspect tachometer periodically
to ensure accuracy within two percent.
(2) Connect tachometer.
WARNING: Use extreme caution when engine is oper
ating. Do not stand in direct line with fan. Do not put
hands near pulleys, belts or fan. Do not wear loose
clothing.
(3) Start engine and warm to normal operating
temperature.
(4) Set parking brake firmly.
(5) Place manual transmission into Neutral.
(6) Adjust idle speed by turning solenoid idle screw
to obtain specified idle speed.
(7) Disconnect solenoid wire connector. Adjust curb
idle screw to obtain 500 rpm.
(8) Connect solenoid wire connector.
(9) Stop engine. Disconnect tachometer. Install air
cleaner (if removed) and connect vacuum hoses (if dis
connected). Connect canister purge hose and deceler
ation valve supply hose (if disconnected).
Carburetor Model 28E Idle Speed
Adjustment Specifications
Engine Transmission RPM
4-Cylinder
Manual
900 (± 100) X
©Idle spetd with solenoid de-energized is 500 rpm.
Fist Idle Speed Adjustment
90978
(1) Connect tachometer.
(2) Set parking brake and place manual transmis
sion in Neutral.
(3) Connect tachometer.
WARNING: Use extreme caution when engine is oper
ating. Do not stand in direct line with fan. Do not put
hands near pulleys, belts or fan. Do not wear loose
clothing.
(4) Start and warm engine to normal operating
temperature.
FUEL SYSTEMS 1J-29
(5) Disconnect and plug EGR valve vacuum hose.
(6) Open throttle slightly and rotate fast idle cam
until adjustment screw is against highest step of cam.
(7) Adjust fast idle speed to specification.
(8) Quickly open throttle slightly and allow engine
to return to slow idle speed.
(9) Connect EGR valve vacuum hose.
(10) Disconnect tachometer.
Idle Mixture Adjustment
Idle mixture adjustment should only be performed if
the mixture adjustment screw position was disturbed or
replaced during carburetor overhaul.
(1) Position manual transmission in Neutral posi
tion. Set parking brake.
WARNING: Use extreme caution when engine is oper
ating. Do not stand in direct line with fan. Do not put
hands near pulleys, belts or fan. Do not wear loose
clothing.
(2) Connect tachometer, start engine and warm to
operating temperature.
NOTE: Use a tachometer with an expanded scale of400
to 800 or 0 to 1000 rpm. Inspect tachometer periodically
to ensure accuracy within two percent.
(3) Adjust idle speed as described above.
(4) Turn idle mixture adjustment screw lean (clock
wise) until perceptible loss of rpm is noted.
(5) Turn idle mixture adjustment screw rich
(counterclockwise) until highest rpm is attained. Do not
turn screw any further than position where highest rpm
is first attained. This is referred to as lean best idle.
NOTE: Engine speed will increase above idle speed an
amount that corresponds approximately to the lean drop
specification obtained in step (6).
(6) As final adjustment, turn idle mixture adjust
ment screw clockwise in increments until specified drop
is attained. Refer to Idle Drop Specification.
NOTE: If the final rpm differs more than ± SO rpm
from the originally adjusted idle speed, readjust idle
speed to specification and repeatsteps (6)and (7).
Carburetor Model 2SE Idle Mixture
Adjustment Idle Drop
Engine
Transmission
RPM Orop
4-Cylihder
M
100
90979
Choke Mechanism Service
Test the choke mechanism and vacuum break for
proper operation at the recommended maintenance in
tervals. Any binding condition that may have developed