Exhaust Systems; Exhaust Manifolds - Jeep J-10 Series 1982 Technical & Service Manual

1K-1
EXHAUST
SYSTEMS
SECTION INDEX
Air Injection Systems
Catalytic Converter Systems
Page
1K-7
1K-13
Pige
Exhaust Manifolds. Mufflers and Pipes 1K-1
EXHAUST MANIFOLDS,
MUFFLERS AND PIPES
Exhaust Manifold Replacement
General
Exhaust Manifold Heat Valve
Muffler Replacement
Page
1K-4
1K-1
1K-4
1K-5
GENERAL
The basic exhaust system for all Jeep vehicles consists
of exhaust manifold(s), front exhaust pipe, catalytic con
verter, muffler and tailpipe.
NOTE: All reference to CJ vehicles includes Scrambler
vehicles.
CJ vehicles with four- or six-cylinder engines that are
designated 49-State use a conventional oxidizing cataly
tic (COC) pellet-type converter (figs. 1K-1 and 1K-2).
Four-cylinder engine CJ vehicles manufactured for sale
in California use a three-way catalytic (TWC) pellet-
type converter. Six-cylinder engine CJ vehicles manu
factured for sale in California and all six-cylinder engine
Cherokee, Wagoneer and Truck vehicles use a dual bed
(COC and TWC) monolithic-type converter with "down
stream" air injection (figs. 1K-2 and 1K-3).
Eight-cylinder engine Cherokee, Wagoneer and Truck
vehicles designated 49-State use a conventional oxidiz
ing catalytic (COC) pellet-type converter (fig. 1K-4).
The exhaust system must be properly aligned to pre
vent stress, leakage and chassis contact. If the system
contacts any body panel, it may amplify objectionable
noises originating from the engine or the body. When
inspecting an exhaust system, inspect for cracked or
Pipe Replacement
Restricted Exhaust System Diagnosis
Specifications
Page
1K-6
1K-1
1K-6
loose joints, stripped screw threads, and corrosion dam
age. Inspect for worn or broken hangers. Replace all
components that are badly corroded or damaged. Do not
attempt to repair.
RESTRICTED EXHAUST SYSTEM DIAGNOSIS
A restricted or blocked exhaust system usually results
in loss of power or backfire up through the carburetor.
Verify that the condition is not caused by ignition tim
ing or other ignition system malfunctions, then perform
a visual inspection of the exhaust system. If the restric
tion cannot be located by visual inspection, perform the
following test procedure.
(1) Attach vacuum gauge to intake manifold.
(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 observe vacuum gauge. Gauge
should indicate 16 to 21 in. Hg (54 to 71 kPa) of vacuum.
(4) Increase engine speed to 2,000 rpm and observe
vacuum gauge. Vacuum will decrease when engine speed
is increased rapidly, but should settle at 16 to 21 in. Hg
(54 to 71 kPa) and remain steady. If vacuum decreases