1953 JEEP CJ ECO mode

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

E
is generally caused by excessive
engine
idle speed

in
combination with retarded ignition timing,

engine
heat soak or the use cf low octane fuel.
Should
engine
dieseling
(engine
running after ignition key is turned off) be experienced on V-6

engine
equipped vehicles, installation of Idle Stop
Valve
Kit
Part
No.
991722
will
correct the
difficulty.

E-43.
Fast
Idle Adjustment
No fast idle speed adjustment is required.
Fast

idle is controlled by the curb idle speed adjustment

screw.
If curb idle speed is correctly set and the choke rod is properly adjusted, fast idle speed
will

be correct;

E-44.
Dash Pot Adjustment —
F4
and V-6 Engine

•
Refer to
Figs.
E-27 and E-28. Before adjusting the dash pot, the
engine
idle speed

and
mixture should be correctly adjusted.
With
the

engine
idling at normal operating temperature,
adjust
the dash pot as follows:

The
dash pot adjustment is made with the throttle
set at curb idle (not fast idle). Loosen dash pot lock
nut and
turn
the dash pot assembly until dash pot
plunger contacts the throttle lever without the plunger being depressed.
Then
turn
the dash pot
assembly 2turns against the throttle lever, de­ pressing the dash pot plunger. Tighten the lock nut
securely. As a final check, open carburetor and
allow throttle to snap closed. Time dash pot delay­ ing action from the point where the throttle lever
hits the dash pot to the point where the lever
stops

moving. The dash pot should delay or cushion
closing action for two seconds by saying, "One
thousand and one, one thousand and two."
14204

FIG.
E-27—DASH
POT
ADJUSTMENT—V6
ENGINE
1—
Throttle
Lever
3—Dash Pot
2—
Plunger
4—Lock
Nut
E-45.
FUEL
PUMP
(DOUBLE-ACTION)
—

HURRICANE
F4
ENGINE

•
Early
Models

The
double-action fuel pump consists of a metal
body, a rubber diaphragm, rocker arm, valves,
FIG.
E-28—DASH
POT
ADJUSTMENT—F4
ENGINE

1—
Throttle
Lever
3—Dash Pot
2—
Plunger
4—Lock
Nut springs, gaskets, and a glass sediment bowl complete

with
strainer.
The
metal pump body provides
a
work­
ing housing for the diaphragm, lever, valves, and springs. The fuel pump is mounted on the left side
of the
engine
and is actuated by an eccentric on the
camshaft. An air
dome
is cast into the metal cover
to relieve the carburetor
needle
valve and the fuel
pump diaphragm of excessive pressure when the

carburetor
needle
valve is closed.

Tracing
pump operation from the beginning, the
camshaft eccentric forces the diaphragm up, over­
coming spring pressure.
This
action creates a
partial
vacuum
in the pump chamber.
Fuel
from the main

tank
is forced into the low-pressure pump chamber
through the open disc valve. Incoming fuel supplies
the force necessary to open the valve, which is

a
one-way check valve. As the
engine
camshaft continues to rotate, spring pressure forces the

diaphragm
downward as the pump rocker arm
follows the camshaft eccentric to its low
spot.

The
downward action of the diaphragm
closes

the intake valve and forces fuel to the carburetor

reservoir
through the pump
outlet
valve. Both intake and
outlet
valves are one-way check valves
opened and closed by fuel flow. No mechanical components are required in the control of valve
operation.

Fuel
is delivered to the carburetor only when the float
needle
is off its seat. When the fuel level in the carburetor bowl is high enough for the float to
force the
needle
against its seat, pressure backs up
to the fuel pump air
dome
and causes the diaphragm
to
stop
pumping. In this position, the pump is said
to be balanced because the pressure in the pump- to-carburetor line equals that of the diaphragm

spring.
In this way, fuel from the pump to the
carburetor
is always under pressure. The carburetor

uses
fuel, causing the float to drop and
pull
the

carburetor
needle
valve off its seat. Pressure in the pump immediately drops as fuel is delivered to the

carburetor
reservoir. Almost instantaneously the

diaphragm
again starts operating to pump more 125

FUEL
SYSTEM
|
11893

FIG.
E-29—FUEL
AND
VACUUM
PUMP—F4
ENGINE,
EARLY
MODELS

1—
Cover
Screw
2—
Lockwasher

3—
Diaphragm
Spring
4—
Spring
Seat 5—
Diaphragm
and Rod
6—
Oil
Seal 7—
Valve
Assembly
8— Body
9—
Rocker
Arm Pin Spring
10—
Fuel
Diaphragm
11—
Oil
Seal Retainer
12—
Diaphragm
and Rod 13—
Valve
Retainer
14—
Cover
15—
Gasket

16—
Screen

17—
Bow!

18—
Bail
19—
Gasket

20—
Screw
21—
Rocker
Arm Spring
22—
Link
Spacer
23—
Rocker
Arm

24—
Washer

25—
Body
fuel. The diaphragm can start and
stop
many
times
in
each mile of vehicle operation, but the pump
actuating lihkage is always in operation while the

engine
is running. The fuel pump incorporates a
pulsator and pulsator chamber to dampen the
effect

of pump pressure pulsations on the carburetor

needle
valve.
This
prevents high fuel level in the

reservoir
that would result from the
needle
being

jarred
away from its seat. Also, operating
economy
would be affected because a high fuel level usually results in an over-rich mixture.

The
actuating linkage has its own spring to ensure
continuous contact of the lever to the camshaft
eccentric.

This
fuel pump has a sediment bowl and filtering
screen which is attached to the top of the pump by
a
wire clamp and thumb nut. The screen and sedi­
ment bowl should be cleaned at least twice yearly
to prevent trouble due to a blocked screen or water
freezing. The bowl should be washed and wiped

dry
and the screen dried and then cleaned with a
stiff
brush.
When reassembling the bowl make cer­
tain
that the cork gasket is not broken; reverse it
and
position it flat on the seat, then install the
bowl and tighten the thumb nut securely. After
cleaning, start the
engine
and carefully inspect the
bowl for leakage.

E-46.
Disassembly
Remove the cover plate, gasket, and screen or
bowl clamp, sediment bowl, gasket and screen if so equipped.
Mark
the two castings with a file to
ensure positioning in the same relation upon
assembly. Remove the screws attaching the fuel cover to the pump body. Remove the cover,

diaphragm,
and spring. Remove rocker arm pin,
rocker
arm, and rocker arm spring. Remove the
valve plate screw and separate the valve plate

retainer,
valve gaskets, and valves.

Clean
all parts in cleaning solvent and blow out

with
compressed air. Valves should not be removed

from
the valve housing assembly.
Check
all parts
to see that
they
have not
been
cracked or broken
and
that screw threads have not
been
stripped or
cross threaded. Refer to Par. E-49 for fuel pump
testing. 126

'Jeep9
UNIVERSAL
SERIES
SERVICE
MANUAL

E-59.
Fuel
Pump Installation

a.
Make certain mating surfaces of fuel pump and
engine
cylinder case are clean. Cement a new gasket
to mounting
flange
of fuel pump.
b. Position fuel pump on cylinder block, so that

cam
lever of pump rests on fuel pump cam of cam­
shaft. Secure pump to block with two cap screws

and
lock washers.
c. Connect intake and
outlet
fuel lines to fuel
pump.

E-60.
FUEL
PUMP
(SINGLE-ACTION)
—
HURRICANE
F4
ENGINE
•
Late
Models.

The
Hurricane F4
engine
is equipped with a single-
action fuel pump (Fig.
E-31).
The fuel pump cam lever is activated by an eccentric on the
engine

camshaft. When the carburetor float
needle
valve
closes, accumulation of fuel in the pump
extends

the diaphragm spring.
This
action causes the rocker

arm
linkage to
become
inoperative until the pres­
sure on the diaphragm and spring is reduced. The fuel pump discharge pressure is thus controlled by
the diaphragm spring.
This
provides a steady sup­ ply of fuel to the carburetor at a fairly constant
pressure.

E-61.
Fuel
Pump Removal

To
remove the fuel pump from the
engine,
dis­
connect the inlet and
outlet
fuel lines. Remove
the two fuel pump
body
attaching nuts, lock washers, and washers, and pull the fuel pump and
gasket free of the
engine.

E-62.
Fuel
Pump Disassembly

Note:
The fuel pump is serviced with a repair kit.

Individual
service parts are also available. The
valves are not replaceable but are serviced as part
of the valve housing.

•
Refer to Fig. E-32.

a.
Remove filter bail assembly, bowl,
element,

spring,
and gasket from filter cover. b.
File
a locating
mark
on the
edges
of the valve
housing and the pump body. Remove the six at-

14280
FIG.
E-32—FUEL
PUMp—

HURRICANE F4 ENGINE,
LATE
MODELS

12988

FIG.
E-31—FUEL
.PUMP-

HURRICANE F4 ENGINE,
LATE
MODELS 1—
Bail

2—
Bowl

3—
Spring

4—
Filter
5—
Gasket

6— Pump Body 7—
Gasket

8—
Valve
Assembly 9— Screws 10—
Valve
Housing
11—
Valve
Assembly
12— Screws
13—
Diaphragm
and Oil Seal 14— Pump Body
15—
Cam
Lever
Spring 16—
Cam
Lever

17—
Gasket

18—
Cam
Lever
Pin and Plug 129

'Jeep'
UNIVERSAL SERIES SERVICE
MANUAL

E
possibility of vapor lock by keeping cool fuel from
the tank constantly circulating through the fuel
pump.

Fuel
pump pressure at carburetor (inlet) on Daunt­
less
V6-225
engine
should be 3% lbs.
[0,264
kgm-cm2] minimum at idle with the vapor return
hose

squeezed off. With the vapor return
hose
open
pump pressure should be 2j^ lbs. [0,176 kg-cm2]
minimum.

The
Dauntless V-6
engine
is equipped with a sealed

unit,
non-repairable, single-action fuel pump (Fig.

E-33).

Note:
All Dauntless V-6
engines
are equipped with

a
throw-away can-type gasoline filter installed in
the fuel line
between
the fuel pump and the
car­
buretor.
This
unit must be replaced every
12,000
miles
[19.200
km.] of vehicle operation.

E-68.
Fuel
Pump Removal

To
remove the fuel pump from the Dauntless V-6
engine, disconnect the fuel inlet, fuel
outlet
and fuel return lines from the pump. Remove the two
fuel pump body attaching cap screws and lock

washers.
Pull
the fuel filter bracket free and remove the pump and gasket. Discard pump and gasket.
Install
new pump in reverse procedure of removal.

E-69.
AIR
CLEANER

Servicing
of the air cleaner is properly taken care of as part of the periodic lubrication and servicing of the vehicle. For this reason, air cleaner servicing
information is given in the Lubrication Section.

Refer
to and follow the instructions given there.

E-70. ACCELERATOR LINKAGE
The
accelerator linkage is properly adjusted when
the vehicle leaves the factory. However, in time
components parts
will
become
worn and require re­
adjustment to maintain a smooth even control of
engine
speed. On Models equipped with F4
engines

the adjustment is made at the adjusting block,

Fig.
E-34. Loosen the lock nuts, and adjust the length of the accelerator rod so that when the
car­

buretor throttle valve is wide open the accelerator
treadle
will
just strike the toe board. After correct
adjustment is made tighten both lock nuts firmly.
To
adjust the accelerator linkage on V6
engines

loosen
the lock nuts securing the accelerator rod
housing to its securing bracket and adjust the length
of the accelerator rod so that when the carburetor throttle valve is wide open the accelerator treadle

will
just strike the toe board. After correct adjust­
ment is made, tighten lock nut firmly, see Fig. E-35 for Dauntless V-6 engine.

E-71. FUEL
TANK
AND
FUEL LINES
The
following paragraphs (E-70 through E-73) describe the removal, installation and services to
be performed when replacing the fuel tank or
servicing
the fuel system.

FIG.
E-34—ACCELERATOR LINKAGE,
F4
ENGINE
1—
Grommet

2— Nut and Lockwasher

3—
Throttle
Control
4—
Choke
Control 5—
Treadle
Rod Seal
6—
Accelerator
Treadle
7—
Treadle
Hinge Pin
8—
Treadle
Hinge 9— Nut and Lockwasher
10—
Screw

11—
Accelerator
Rod
12— Nut
13—
Adjusting
Block
14—
Retracting
Spring
15—
Cotter
Pin
16—
Lower
Beilcrank
17—
Washer

18—
Beilcrank
Link
Rod
19—
Bracket

20—
Throttle
Wire
Stop
21—
Beilcrank
Spring
22—
Rod

23—
Upper
Beilcrank
24—
Wesher
10731
131

Fl
EXHAUST EMISSION CONTROL SYSTEMS

12793

FIG.
Fl-1—HURRICANE
F4-134
ENGINE EXHAUST EMISSION CONTROL SYSTEM
1—
Anti-Backfire
Diverter
Valve

2— Air
Pump

3—
Pump
Air
Filter
Injection
Tube(s)
(Inside
Manifold)

5—Air
Delivery
Manifold
6—
Check
Valve
Ignition
timing must be set at 0 or at top dead
center.

Fl-10.
Exhaust Manifold

The
exhaust manifold is provided with a
boss
that is drilled and tapped at each cylinder to accept the

air
delivery manifold and injection tubes.

Fl-11.
MAINTENANCE

Efficient
performance of the exhaust emission con­
trol
system is dependent upon precise maintenance.
In
addition to the air pump and connecting
hoses

and
tubes, this system's efficiency is dependent
upon special carburetor calibration, distributor cen­

trifugal
advance curve and ignition timing setting

which
must be adjusted at 0 or top dead center.

Road
test
is a factory recommended optional serv­ ice every
6,000
miles
[9,600
km.] to evaluate over­

all
performance.

The
following procedure is recommended to assist
in
diagnosing performance and/or emission level
problems that are peculiar to
Exhaust
Emission

Control
System equipped vehicles.

Fl-12.
Carburetor

Check
carburetor number for proper application. (Specifications are listed at the end of this section)

Check
the dash pot and adjust as required.

Proper
carburetor idle mixture adjustment is im­
perative for
best
exhaust emission control.
The
idle adjustment should be made with the en­
gine
at normal operating temperature and air
cleaner
in place. Adjust the throttle
stop
screw to
idle the
engine
at specified RPM. All lights and accessories must be turned off.

Fl-13.
Carburetor
Idle
Setting
NOTE:
The idle mixture adjustment procedure for
the late model
YF-4941S
and
YF-6115S
Carter
Carburetor
equipped with the
External
Idle
Mix­

ture
Limiter
Cap is the same as outlined below
in
Pars.
"A"
through
"D";
however, because of the

Idle
Limiter
Cap,
the idle mixture screw
CANNOT

be adjusted in the counter-clockwise
(rich)
direc­
tion. The adjustment is made from the
rich
stop
position and the mixture screw is turned in (clock­
wise) approximately %
turn
to "Lean Best
Idle."
Refer
to Section E, Fig. E-6.

The
"Lean
Best
Idle"
method of idle setting is as follows:

a.
Any scheduled service of ignition system should
precede this adjustment. 144

'Jeep'
UNIVERSAL SERIES
SERVICE
MANUAL

Fl
Fl-27.
EXHAUST EMISSION CONTROL SYSTEM MAINTENANCE CHART

Efficient
performance of the Exhaust Emission
Control
System is
dependent
upon precise main­tenance. As indicated in the following chart, it is very important that all of the maintenance require­

ments
listed are performed with extreme care at
the specific intervals indicated.

OPERATION
Thousands of miles* or
number of months whichever
occurs first 2
6
12 18
24 30

R R
R R
R R

O O o O
O
o O

R
O
o
o

R
o

o o

o
o

o
O
o
Inspect engine-driven
belts
for condition and tension...
Replace positive crankcase ventilation valve (PCV) Replace filter on exhaust emission control system

Clean
carburetor air cleaner

Engine
tune-up
Check
engine
timing

Adjust
carburetor idle
speed
and mixture

Perform
factory-recommended road
test
for evaluation of overall performance and handling

R
— Required Services
O
— Optional Services
Miles
2,000

6,000

12,000
18,000
24,000
30,000
Kilometers

3,200

9,600

19,200
28,800
38,400 48,000

Fl-28.
EXHAUST EMISSION CONTROL SYSTEM CARBURETOR SPECIFICATIONS

Make
Models

Part
Number
Throttle
Bore
Main
Venturi

Low
Speed Jet

Main
Metering Jet

Idle
Port
Nozzle Bleed in Body
Pump Jet

Float
Level
Dash
Pot Setting

Engine
Idle
RPM:
with Distributor Model
IAY-4401A.
with Distributor Model
IAY-4401B.
Carter
— Single Bore

^ an H
YF
4366S ana 4941S, 6115S

1M"
[3,81 cm.]

IX"
[3,18 cm.]
.035"
[0,889
mm.] .089" [2,26 mm.]
.184" x .030" [4,70 a
0,765]
.028"
[0,713
mm.]
.024"
[0,610
mm.] lW [6,74 mm.]
%"
[3,75 mm.] 650 — 700 700 — 750

Fl-29.
EXHAUST EMISSION CONTROL SYSTEM DISTRIBUTOR SPECIFICATIONS

Engine

Make
Models
Rotation
Point Opening

Breaker
Lever
Tension..
Cam
Angle (Dwell)
Condenser Capacity
Dist.
Degrees and RPM:
Start..

Intermediate

Maximum

TIMING:
Crankshaft

Mark
Location

Firing
Order
F4-134
Prestolite

IAY-4401A

CCW
Rotor End
.020"
[0,508
mm.|
17 — 20 ozs. [482 a 567 gr.l
42°

.25 — .28 mfd.

0°
— 300
3°
— 375

13.5°
— 1700

0°
TDC @ Idle

Crankshaft
Pulley
1-3-4-2
Prestolite

IAY-4401B

CCW
Rotor End
.020"
[0,508
mm.]
17 — 20 ozs. [482 a 567 gr.
42°

.25 — .28 mfd.

0°
— 450

4.5°
— 550

13.5°
— 1700

0°
TDC @ Idle

Crankshaft
Pulley
1-3-4-2

Fl-30.
SPARK PLUG
GAP

Spark
Plug Gap. .030"
[0,765
mm.] 147

Fl

EXHAUST
EMISSION
CONTROL
SYSTEMS
IMPORTANT
NOTICE

The
Exhaust
Emission Systems covered
in
this publication
meet
State and

Federal
requirements for hydrocarbon and carbon
monoxide
emissions.

To
assure continued proper operation,
these
systems
must
be
inspected

regularly,
parts must be replaced
at
factory-recommended intervals and
engine

tune-up services performed at intervals specified in the
Exhaust
Emission
Con­
trol
System Maintenance charts.

For
the
above
reasons,
these
systems
must not, under any circumstances,
be

altered
to anything other than
required
specifications provided in this publication.

Further,
the
Exhaust
Emission
Control
System, or any
of
its components, must
not be physically altered or modified in any respect.

DHTfl
TAG

For
the serviceman's guidance, each vehicle equipped with exhaust emission

control
will
have data
tag
permanently affixed
to the
radiator shroud—-in
example:

VEHICLE
EMISSION
CONTROL
INFORMATION
MODEL
F4-134
C.I.D.

•
ENGINE
AT
NORMAL
OPERATING
TEMPERATURE

•
LIGHTS
AND
ALL
ACCESSORIES OFF

•
IDLE
MIXTURE
. . .
LEAN
BEST
IDLE

•
IGNITION
TIMING
0*
(TDC)
•
SPARK
PLUG
GAP
. . . .030

•
DWELL
...
42* (.020
POINT
GAP)
•
IDLE
SPEED
. . .
700-750 RPM
TRANSMISSION
IN
NEUTRAL
DURING
TUNE
UP

SEE SERVICE MANUAL
FOR
ADDITIONAL INFORMATION
THIS VEHICLE CONFORMS
TO U.S.
DEPT.
OF
H.E.W.
REGULATIONS APPLICABLE
TO
1971 MODEL YEAR NEW MOTOR VEHICLES

Jeep
CORPORATION
14401

Important:
Always refer
to
the data tag when checking or re-adjusting ignition

timing,
idle speed, and idle mixture. 148

F2
EXHAUST EMISSION CONTROL SYSTEMS
F2-3L
EXHAUST EMISSION CONTROL SYSTEM
DIAGNOSIS
GUIDE

Pump Noisy
Hoses Touching Other Parts of Engine or Body (Hood).

Note:
The Air Pump is not completely noiseless.

Under
normal conditions, pump
noise
rises in pitch as
engine
speed
increases. It is desirable to allow
for normal break-in wear of the pump prior to re­
placement for
excessive
noise.
Pump Seized
Replace pump.
-
do not pry on housing.
Leak
In Hose

Check
for leaks; using
soap
and water, tighten clamps or replace
hoses.

Pump Inoperative
Loose Belt — tighten belt
-

Filter
Plugged — replace.

Exhaust
Backfire

Check
for vacuum leaks — correct as necessary.
Check
anti-backfire valve — replace as necessary
Induction System Backfire

Verify
engine
timing and distributor dwell.
Verify
accelerator pump charge.

F2-32.
EXHAUST EMISSION CONTROL SYSTEM MAINTENANCE CHART

Efficient
performance of the Exhaust Emission very important that all of the maintenance require-

Control
System is
dependent
upon precise main-
ments
are performed with extreme care at the
tenance. As indicated in the following chart, it is specific interval indicated.
Thousands of miles* or

OPERATION
number of months whichever occurs first 2 6 12 18 24 30
Inspect engine-driven
belts
for condition and tension R R
Replace positive crankcase ventilation valve
(PCV)
R R

Check
for free operation of exhaust manifold heat control valve O O O O O

Clean
carburetor air cleaner — Oil Bath O O O O O
Replace carburetor air cleaner
element
— Dry Type O
Check
heated air system O O

Engine
tune-up O O

Check
engine
timing R O O O
Adjust
carburetor idle
speed
and mixture R O O O

Perform
factory-recommended road
test
for evaluation of overall performance and handling O O O O O

R
— Required Services O — Recommended Services

*
Miles Kilometers
2,000
—
3,200

6,000
—
9,600

12,000
—
19,200 18,000
—
28,800
24,000
—
38,400
30,000
—
48,000

F2-33.
GENERAL SPECIFICATIONS
Air
Pump Belt Tension 60 lb.

Rotor
Ring Screw Torque . 37 lb-in.
Housing Cover Bolt Torque 10 lb-ft. Speed Ratio, Air Pump to Engine
1
\i to 1

F2-34.
EXHAUST EMISSION CONTROL SYSTEM CARBURETOR SPECIFICATIONS

Make
Rochester Model Designation 2G Code Number
7027082
—
7041185

Choke
Manual
Number of Barrels 2

Throttle
Bore... \W [3,65 cm.]
Main
Metering Jet Production .051" - 60° [1,29 mm.]
High
Altitude — over
5000
ft .049" - 60° [1,24 mm.]
—
over
10,000
ft .047" - 60° [1,19 mm.]

Float
Level
Adjustment* 1%," [2,94 cm.]
Float
Drop Adjustment l%" [4,76 cm.]
Pump Rod Adjustment** 1%" [2,94 cm.]
Engine
Idle
R.P.M.
(In Neutral) 650 to 700

Initial
Idle Speed-screw
setting
3 turns in

Initial
Idle Mixture-screw
setting
2 turns out
Dash
Pot Setting. Y%w [3,75 mm.]
*From
air horn gasket to top of float at toe.

**From
air cleaner ring to top of pump rod.
158