Sealed Idle Mixture Screw; Carburetor Replacement; Carburetor Overhaul - Jeep J-10 Series 1982 Technical & Service Manual

U-16 FUEL SYSTEMS
SEALED IDLE MIXTURE SCREW
The idle mixture screwis recessed in the throttle body
and sealed with a hardenedsteel plugto preventchang
ing the factory assembly adjustment of the air/fuel
mixture ratio. Do not remove the plug and readjust
the idle mixture screw unless involved in a major
carburetor overhaul, throttle body replacement or the
presence of high idle CO has been determined by a
competent authority.
CARBURETOR REPLACEMENT
Removal
Flooding, hesitation on acceleration and other per
formance complaints are, in many instances, caused by
the presence of dirt, water or other foreign matter in the
carburetor. To aid in diagnosis, the carburetor should be
carefully removed from the engine without draining fuel
from the bowl. The contents of the fuel bowl can then be
examined for contamination as the carburetor is dis
assembled. Also, the filter should be examined to deter
mine if it should be replaced.
WARNING: Battery negative cable must be removed
to prevent a potential fire hazard when the fuel pipe
fitting is disconnected.
(1) Remove battery negative cable.
(2) Remove vacuum hoses, air cleaner and gasket.
(3) Disconnect fuel pipe fitting and vacuum hoses
from carburetor.
NOTE: Identify and tag vacuum hoses before dis
connecting them.
(4) Disconnect throttle linkage and electrical
connectors.
(5) Remove carburetor attaching bolts and nuts,
and remove carburetor and gasket.
Installation
Fill the carburetor bowl before installing carburetor.
This reduces the strain on the battery and the possibility
of backfire when attempting to start the engine.A small
quantity of no-lead fuel will also allow a pre-test of the
operation of the float and inlet needle and seat assem
bly. Operate the throttle lever several times and observe
the discharge from the pump jets before installing the
carburetor.
(1) Ensure throttle body and intake manifold mat
ing surfaces are clean.
(2) Install manifold gasket on replacement
carburetor.
(3) Place carburetor in position and loosely install
attaching bolts and nuts.
(4) Connect vacuum hoses and loosely connect fuel
pipe fitting.
(5) Tighten attaching bolts and nuts with 12 foot
pounds (16 N*m) torque.
(6) Tighten fuel pipe fitting with 25 foot-pounds (34
N»m) torque.
(7) Connect throttle linkage and electrical
connectors.
(8) Connect battery negative cable.
NOTE: Plug disconnected vacuum hoses.
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.
(9) Adjust idle speed rpm. Refer to Specifications.
(10) Install air cleaner, gasket and connect vacuum
hoses.
CARBURETOR OVERHAUL
The following procedures apply to a complete over
haul with the carburetor removed from the engine.
A complete disassembly is not necessary for per
forming routine service adjustments. Also, in most in
stances, service adjustments of individual circuits can
be completed without removing the carburetor from the
engine. Refer to Service Adjustment Procedures.
A complete carburetor overhaul includes disassembly,
thorough cleaning, inspection and replacement of all
gaskets and worn or damaged parts. It also includes idle
speed adjustment, idle mixture adjustment (if removal
of adjustment screws was necessary) and fast idle ad
justment after the carburetor is reinstalled.
NOTE: When using an overhaul kit, use all parts in
cluded in the kit.
NOTE: Flooding, hesitation on acceleration, and other
performance problems are in many instances caused by
the presence of dirt, water, or other foreign matter in
the carburetor. To aid in diagnosing the problem, care
fully remove the carburetor from the engine without
removing the fuel from the bowl Examine the bowl
contents and filter for contamination as the carburetor
is disassembled.
CAUTION: Before performing any service on the car
buretor, it is essential that the carburetor be placed on
an appropriate holding fixture. Without the use of the
holding fixture, it is possible to damage the throttle
valves.
Disassembly
(1) Remove pump lever retaining screw from air
horn (fig. 1J-27). Rotate pump lever to remove from
pump rod.