Vacuum Piston Adjustment; Initial Choke Valve Clearance Adjustment - Jeep J-10 Series 1982 Technical & Service Manual

1J-56 FUEL SYSTEMS
Fig. 1J-109 Vacuum Piston Adjustment
Vacuum Piston Adjustment
(1) Adjust gap in vacuum piston to specification.
(2) Back off idle speed adjustment screw until
throttle valves are completely closed. Count number of
turns and note so that screw can be returned to original
position. Turn idle speed adjustment screw until it
barely contacts stop, then turn one full turn further.
(3) Fully depress vacuum piston while holding mod
erate pressure on rod lifter tab. While in this position,
tighten rod lifter lock screw (fig. U-109).
(4) Release piston and rod lifter.
(5) Adjust accelerator pump as outlined below.
(6) Return idle speed adjustment screw to its origi
nal position.
(7) Install dust cover.
Accelerator Pump Adjustment
(1) Remove dust cover.
(2) Back off idle speed adjustment screw to com
pletely close throttle valves. Open choke valve so that
fast idle cam allows throttle valves to seat in bores.
(3) Turn idle speed adjustment screw in until it
barely contacts stop. Then continue two complete turns.
(4) Measure distance between surface of air horn
and top of accelerator pump shaft (fig. 1J-110). Refer to
Specifications for correct dimension.
(5) Loosen pump arm adjustment lock screw and
rotate sleeve to adjust pump travel to correct distance.
Tighten lock screw.
(6) Install cover and screws.
PUMP ARM
LOCK
SCREW
rA5
ACCELERATOR
PUMP SHAFT
80447
Fig. U-l 10 Accelerator Pump Adjustment
Initial Choke Valve Clearance Adjustment
NOTE: The choke should not normally require read
justmentfrom the originalfactory assembly adjustment
except after a major overhaul.
(1) Grind off torque-head screw heads and remove
remaining portions of screws by turning counter
clockwise with locking pliers. Turn choke cover 1/4 turn
rich. Retain in position with one straight-slot screw.
(2) Open throttle valve slightly to place fast idle
screw on high step of cam.
(3) Use Tool J-23738 or any vacuum source that
holds at least 19 inches of mercury (19 in. Hg/64 kPa) to
pull in diaphragm against stop.
(4) Measure clearance between choke plate and air
horn wall. Refer to Specifications.
(5) Adjust clearance by bending diaphragm con
nector link (fig. 1J-111).
(6) Remove straight-slot screw and adjust cover in
dex to specified notch. Install replacement torque-head
(break off) screws.
NOTE: Head of screws will break off when tightened
beyond the calibrated torque.
Fast Idle Cam Position Adjustment
(1) Remove torque-head screws and position choke
cover 1/4 turn rich. Retain with one straight-slot screw.
(2) Open throttle slightly and place fast idle screw
on second step of cam.
(3) Measure distance between choke plate and air
horn wall (fig. 1J-112). Refer to Specifications for cor
rect dimension.
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