fuel pump JEEP DJ 1953 Workshop Manual

E

FUEL
SYSTEM
E-55.
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.
FIG.
E-30
—
FUEL
PUMP—HURRICANE

F4 ENGINE,
EARLY
MODELS
1—
Housing
Cover

2— Air
Dome
Diaphragm

3—
Strainer

4—
Screw
and
Washer

5—
Housing

6—
Cover
Screw
and
Lock
Washers
7—
Main
Diaphragm

8—
Pump
Body

9— Cam
Lever
Return
Spring

10— Pin
Retainer

11— Cam
Lever

12— Cam
Lever
Pin

13—
Lever
Seal
Shaft
Plug
E-56.
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.

a.
Before disassembly of the fuel pump,
mark
the
three castings (see Fig. E-30) to ensure positioning

in
the same relation upon assembly. b. Remove the inlet and
outlet
fuel fittings from
the pump.
c. Remove the screws and washers and separate the housing from the pump body.

d.
Remove cover screws and lock washers and
then remove housing cover,
dome
diaphragm and

strainer.

e.
Remove cam lever return spring and lever seal
shaft plug.
f. Remove retainer pin, cam lever pin and cam
lever.
g. Remove main diaphragm.

Note:
Do not remove valves from housing as they

are
serviced with the housing.

Note:
The oil seal (at top of spring in diaphragm
assembly) seals the spring side of the fuel
dia­

phragm
from the crankcase. Any deposit, in
excess

of a few drops, of oil on the diaphragm, indicates
leakage past the oil seal. Be sure the seat for the
seal
in the pump body is clean and smooth.

E-57.
Fuel
Pump
Cleaning
and
Inspection

Caution:
Do not immerse valves or diaphragm in
-cleaning solvent; wipe clean.

Clean
all metal parts of the fuel pump in solvent.
Brush
with a stiff-bristled brush. Dry with com­
pressed air.
Check
all parts to see that they are not

cracked
or broken and that the screw threads are
not damaged.

E-58.
Fuel
Pump
Reassembly

a.
Position the new main diaphragm on pump body
and
hold it in position while installing cam lever

in
position.
b.
Install
cam lever pin, pin retainer and lever

seal
shaft plug.
c.
Install
cam lever return spring.

d.
Position strainer, air
dome
diaphragm and hous­
ing cover on housing and secure with screw and
lock
washers.

e.
Position housing on pump body and secure with screw and washers.
First
start all screws one or
two turns:
Then
tighten the screws alternately and
securely.

Note:
Before placing housing on pump body
note

position of align marks made before disassembly.
f.
Install
the fuel inlet and
outlet
fittings.

Note:
Lubricate
forked end of cam lever and cam
lever pin.

Caution:
Do not overtighten screw. 128

'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

E

FUEL
SYSTEM
taching screws and valve housing from the fuel
pump body.

c.
Remove the two screws in the valve housing
and
separate the filter cover and air
dome
dia­
phragm.

d.
Remove the cam lever return spring, plug,
cam
lever pin, and cam lever from the pump body.

Tap
the cam lever pin out of body, using a drift
inserted through the small
hole
in the pump body.
e. Remove diaphragm from pump body.
f. Under normal service, the pump may be cleaned without further disassembly.

Note:
The oil seal (at top of spring in diaphragm
assembly) seals the spring side of the fuel
dia­
phragm
from the crankcase. Any deposit, in
excess

of a few drops, of oil on the diaphragm indicates leakage past the oil seal. Be sure the seat for the

seal
in the pump body is clean and smooth.

E-63.
Fuel
Pump Cleaning and Inspection

Caution:
Do not immerse valves or diaphragm
in
cleaning solvent; wipe clean.

Clean
all metal parts of the fuel pump in solvent.
Brush
with a stiff-bristled
brush.
Dry with com­
pressed
air.
Check
all parts to see that they are not
cracked
or broken and that the screw threads are
not damaged.

E-64.
Fuel
Pump Reassembly
•
Refer to Fig. E-32.

a.
Assemble the valve housing and filter cover, using a new air
dome
diaphragm. The opening

in
the air
dome
diaphragm is located over the
intake
valve. The filter cover is positioned cor­
rectly
when the inlet passage in the cover aligns

with
the inlet valve. Tighten the attaching screws
alternately and securely.

b.
Lubricate
diaphragm assembly shaft, around

oil
seal, with
engine
oil. Position diaphragm as­ sembly on valve housing and thread all the attach­ ing screws through diaphragm.
(This
helps avoid
damage to the screw
holes
in diaphragm.)

c.
Place diaphragm assembly and valve housing
in
position on pump body (align marks made
before disassembly).
First
start all screws one

or
two threads; then tighten the screws alternately

and
securely.

d.
Lubricate
forked end of cam lever, pin bore
of body, and corresponding
hole
in lever, and the
pin
itself with
engine
oil.

Note:
Forked
end of lever
goes
around diaphragm
shaft. Be sure
loose
bumper washer on diaphragm shaft is on top of lever and
between
lever and fixed
washer
on shaft.
e.
Install
lever and pin. To install pin, use a drift
and
tap pin into the
hole
in the body until it hits
the
stop
on the
bottom
of the hole;
move
the lever while tapping, to align
hole
in lever with the pin;
then install plug.
Install
lever return spring.
f.
Install
a new filter bowl gasket in filter cover.
Place
bail
assembly in ears on cover and swing
to one side.
Install
spring and new filter element in
bowl and install bowl on pump. Position
bail
as­
sembly under bowl; tighten retainer screw.

Caution:
Do not overtighten screw.

E-65.
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. Torque
bolts
13 to 17 lb-ft. [1,8
a
2,3 kg-m.].

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

E-66.
Fuel
Pump Testing

Whenever
the fuel pump is to be checked for pres­

sure
or volume, follow the procedure outline in

Par.
C-23 of this manual.
Fuel
pump pressure is
important
for low pressure
will
seriously affect en­

gine
operation and high pressure can cause exces­
sive fuel consumption and flooding of the carbure­
tor.
Should there be any doubt of normal opera­
tion, check the procedure as outlined in Par. C-23.
In
addition to proper fuel pressure, volume of the
pump is also important. When testing for proper
pump pressure, be certain to also
test
for volume
as the pump may build up sufficient pressure, but
fail
to produce sufficient volume.

E-67. FUEL
PUMP
—
DAUNTLESS
V-6
ENGINE

Jeep vehicles equipped with the Dauntless V6-225

engine
have a special fuel pump which has a metering
outlet
for a vapor return system. Any

vapor
which forms is returned to the fuel tank
along with hot fuel through a separate line along­
side the fuel supply line.
This
greatly reduces any
FIG.
E-33—FUEL PUMP—DAUNTLESS V-6 ENGINE
1
—Fuel
Outlet 2—Vapor
Return
3—Fuel
Inlet

130

'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

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

E
portant that
these
lines are not accidentally re­
versed.

When
installing the fuel tank on late model vehicles, position the tank
between
the frame
rail

to allow space to connect the fuel line(s), vent
hose

and
sending unit wire. After connecting
these
items, align and secure tank to frame brackets.
Position filler
hose
on tank filler neck and tighten
hose
clamp.
Fill
tank with fuel and check for leaks.

When
installing the fuel tank on early model vehicles, reverse the order of removal as given in

Par.
E-73.

E-75.
Fuel
Tank
Cap

A
surge pressure type fuel tank filler cap is used on

all
models.
This
is necessary to prevent fuel leakage
from
the cap vent opening when the vehicle is on a
side slope. Two spring loaded relief valves which
open when venting is required are built into the
cap.
Should the pressure valve
fail
to open, pressure
in
the tank may force fuel by the carburetor inlet
valve causing flooding.
Failure
of the vacuum valve may prevent flow of fuel to the carburetor. Should
the valves
fail
to vent install a new cap.

Note:
Vehicles having a
Fuel
Evaporative
Emis­

sion System are equipped with a non-vent sealed gas cap. The sealed cap is designed to allow no
vapors to discharge to the atmosphere. No other type of cap is to be used on vehicles having this
type system.

E-76.
Fuel
Gauge Float Unit

The
fuel tank
gauge
float unit is mounted in the top
of the fuel tank and consists of a housing enclosing
a
rheostat that is actuated by the float arm, and a
float
which
moves
with the fuel level in the tank.
On
V-6 and current production F4
engine
equipped vehicles, the fuel
outlet
pipe is integral with the
float
unit.
The fuel
outlet
pipe has a mesh filter on the inner end.

Note:
Under no circumstances should a fuel tank

gauge
be installed without a mesh filter element.

The
filter,
outlet
pipe, and float unit are locked as

an
assembly to the top of the fuel tank. To remove,

turn
the lock plate that secures the float unit
assembly.

E-77.
Fuel
Lines

Check
lines and connections occasionally for leaks,
and
for severe kinks that might restrict the flow of
fuel. If an excessive amount of
dirt
is found in the
carburetor
or fuel pump, the fuel tank should be
drained
and the fuel lines blown out with com­
pressed air.

All
rubber fuel lines and their respective clamps should be checked occasionally to be certain they
are
correctly positioned and not leaking. 133

E

FUEL
SYSTEM
E-78. SERVICE DIHGNOSIS
Symptoms Probable Remedy

Excessive
Fuel
Consumption:
Tires
improperly inflated Inflate

Brakes
drag Adjust
Engine
operates too cold Check thermostat
Heat control valve inoperative Check thermostatic spring
Leak
in fuel line Check all connections

Carburetor
float level high. See
"Carburetor"
section
Accelerator pump not properly adjusted Adjust

Leaky
fuel pump diaphragm Replace
Loose
engine
mountings causing high carburetor fuel level Tighten Ignition timing slow or spark advance stuck See "Distributor" section

Low
compression. Check valve tappet clearance
Air
cleaner dirty
.
Remove and clean

Engine
Hesitates on Acceleration: Accelerator pump
does
not function perfectly.
...................
.Replace piston and rod or adjust
Carburetor
float level. ... .Adjust

Spark
plugs Replace or clean and adjust

Low
compression Check valves

Distributor
points—dirty or pitted Replace

Weak
condenser or coil Replace

Carburetor
jets restricted Remove and clean

Excessive
engine
heat See "Engine" section

Engine
Stalls—Won't Idle:
Improper
condition of carburetor See
"Carburetor"
section

Low
speed
jet restricted Remove and clean
Dirty
fuel sediment bowl screen Remove and clean

Air
cleaner dirty Remove and clean

Leaky
manifold or gasket Replace

Fuel
pump diaphragm porous. Replace
Loose carburetor. Tighten
flange
nuts

Water
in fuel
Drain
and clean system

Improper
ignition. .See "Distributor" section

Spark
plugs Clean and adjust

Valves
sticking.
Grind
valves 134

'Jeep'
UNIVERSAL SERIES
SERVICE
MANUAL

E
E-79.
FUEL
SYSTEM SPECIFICHTIONS
CARBURETOR SPECIFICATIONS HURRICANE
F4 (See
Note)

Make
Model.
Throttle Bore

Main
Venturi.
Low
Speed
Jet

Main
Metering Jet Idle Port

Nozzle
Bleed In Body
Pump Jet
Float
Setting

Engine Idle RPM Dash Pot
Setting
. ......

CARBURETOR SPECIFICATIONS HURRICANE
F4 (See
Note).

Make Model
Throttle Bore
Main
Venturi
Low
Speed
Jet
Main
Metering Jet Idle Port

Nozzle
Bleed In Body
Pump Jet.
Float
Setting
Engine Idle RPM Dash Pot
Setting
Without Exhaust Emission Control

Carter

YF-938SD

lY2n
[3,81 cm.]

1M"
[3,18 cm.]
.028"
[0,711
mm.]

.0935"
dia.
[2,375
mm.]
.184" x .030" [4,70 a
0,765
mm.]
.0225
"[0,571
mm.] .031"
[0,787
mm.] Vk" [7,39 mm.] 600 Without Exhaust Emission Control

Carter

YF-4002-S

\y%"
[3,81 cm.]

1M"
[3,18 cm.]
.031"
[0,794
mm.]
.091" dia.
[2,311
mm.]
.184" x .030" [4,70 a
0.765
mm.] .028"
[0,713
mm.]
.025"
[0,635
mm.]
lW
[6,74 mm.] 650 — 700

With
Exhaust Emission Control
Carter

YF-4366-S,
YF-4941-S, YF-6115-S IV2" [3,81 cm.]

1M*
[3,18 cm.]
.035"
[0,889
mm.]
.089" dia.
[2,261
mm.]
.184" x .030" [4,70 a
0.765
mm.] .028"
[0,713
mm.]
.024"
[0,609
mm.]
1W
[6,74 mm.] 700 - 750
Y%" ]3,75 mm.]

CARBURETOR SPECIFICATIONS
DAUNTLESS
V-6 (See
Note)
Make
Model
Designation
Code Number
Choke
Number of Barrels
Throttle Bore

Main
Metering Jet: Production . . High Altitude —
over
5000
ft
—
over
10,000
ft... .
Float Level Adjustment*
Float Drop Adjustment Pump Rod Adjustment**
Engine Idle RPM
Initial
Idle
Speed
Setting
Initial
Idle Mixture
Setting.

Dash Pot
Setting
Without Exhaust Emission Control
Rochester
2G

7026082
Manual
2
Wy? [3,65 cm.]
.051" - 60° [1,29 mm.]
.049" - 60° [1,24 mm.] .047" - 60° [1,29 mm.]
Hit"
[27,78
mm.] V/%" [4,76 cm.]

IH2"
J2.94 cm.] 650
-—
700 3 turns in
2 turns out
W [3,75 mm.]
With
Exhaust Emission Control
Rochester

2G

7027082-7041185
Manual

2
[3,65 cm.]
.051" - 60° [1,29 mm.]
.049" - 60° [1,24 mm.] .047" - 60° (1,29 mm.] l%2"
[29,36
mm.] V/£" [4,76 cm.]

\W
]2,94 cm.[ 650 — 700 3 turns in
2 turns out
[3,75 mm.]

*From
air horn
gasket
to top of
float
at toe.

**From
air cleaner ring to top of
pump
rod.
NOTE:
Carburetor
specifications
for
engines
equipped
with
exhaust
emission
control are
also
shown
in
section
Fl for the F4-134 Hurricane
engine,
and in
section
F2 for the V6-225 Dauntless
engine.
135

E

FUEL
SYSTEM E-79.
FUEL
SYSTEM SPECIFICATIONS
(Continued)

MODEL
EARLY
MODEL
HURRICANE
F4
EARLY
MODEL
DAUNTLESS
V-6

AIR CLEANER:
Type
Oil
Bath

Oil
Bath

FUEL
TANK: 10H
gal. [39,75 ltr.]
10lA
gal. [39,75 ltr.]

Location
Under
Driver's Seat

Under
Driver's Seat

FUEL
PUMP:
AC
or
Carter
A.C.

Model
5594032
21955

6440515

Type..
Diaphragm,
serviceable unit
Disposable unit

FUEL
FILTER:
Tank
unit only
Left
side of engine, plus tank unit

MODEL
LATE
MODEL
HURRICANE
F4
LATE
MODEL
DAUNTLESS
V-6

AIR CLEANER:
Type...
Oil
Bath

Dry
Type

FUEL
TANK:
Capacity
16 gal. [60,57 ltr.]
16 gal. [60,57 ltr.]
Between frame
rails,
rear
of vehicle Between frame
rails,
rear
of vehicle

FUEL
PUMP:
Make.
Carter

A.C.

Model.
. 4574-S

6440515

Type
Diaphragm,
serviceable unit
Disposable unit

FUEL
FILTER:
Left
side of engine, plus tank unit
Left
side of engine, plus tank unit 136

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

Fl
b. Connect tachometer to
engine.

c.
Warm
up
engine
and stabilize temperatures.

d.
Adjust
engine
idle to
speed
desired, using throt­
tle idle
speed
adjusting screw.

e.
Carburetors without Idle
Limiter
Cap turn idle mixture screws out (counterclockwise) until a
loss

of
engine
speed
is indicated; then, slowly turn mix­
ture screw in (clockwise-leaner) until maximum

speed
(RPM) is reached. Continue turning in (clockwise) until
speed
begins
to drop; turn mixture
adjustment back out (counterclockwise-richer) un­

til
maximum
speed
is just regained at a "lean as
possible" mixture adjustment.

Fl-14.
Distributor

Check
the distributor number for proper appli­
cation.
Check
the distributor cam dwell angle and
point condition and adjust to specifications or re­ place as required. (Specifications listed at the end
of this section)
Check
ignition timing and set at

0°
or
TDC.

Fl-15.
Anti-iackfire
Diverter Valve

The
anti-backfire valve remains closed
except
when
the throttle is closed rapidly from an
open
position.

To
check the valve for proper operation, accelerate
the
engine
in neutral, allowing the throttle to
close

rapidly.
The valve is operating satisfactorily when
no exhaust system backfire occurs. A further check
to determine whether the valve is functioning can be made by removing from the anti-backfire valve
the large
hose
Which
connects to the check valve.
Accelerate the
engine
to allow the throttle to
close

rapidly.
The valve is operating satisfactorily if a
momentary interruption of rushing air is audible.

Fl-16.
Check Valve

The
check valve prevents the reverse flow of ex­
haust
gases
to the pump in the
event
the pump
should, for any reason,
become
inoperative or should exhaust pressure ever
exceed
pump pressure.

To
check this valve for proper operation, remove the air supply
hose
from the pump at the
distri­

bution manifold.
With
the
engine
running, listen for exhaust leakage at the check valve which is
connected to the distribution manifold.

Fl-17.
Air
Pump

Check
for proper drive belt tension with belt tension
gauge
W-283. The belt strand tension should be

50-60
pounds on a belt with previous service, meas­

ured
on the
longest
accessible span
between
two pulleys. When installing a new belt, adjust the
tension to
60-80
pounds tension. DO NOT PRY
ON
THE DIE
CAST
PUMP
HOUSING.

To
check the pump for proper operation, remove the air
outlet
hose
at the pump.
With
the
engine

running,
air discharge should be
felt
at the pump

outlet
opening. The pump
outlet
air pressure, as determined by the relief valve, is preset and is not
adjustable.

The
air pump
rear
cover assembly, housing the pressed in inlet and discharge tubes, and the pres­
sure relief valve are the only pump
components

recommended for service replacement. These parts
are
to be replaced only when damaged as a result
of handling or in the
event
the relief valve was
tampered with.

Fl-18.
Carburetor
Air
Cleaner

Every
6000
miles
[9,600
km.] clean the inside
sur­

face at the sump and
refill
to indicated oil level with
SAE
40 or 50
engine
oil
above
32 F; SAE 20

below
32 F. Wash filter
element
in kerosene and

drain.
Reassemble the air cleaner.

More
frequent cleaning and replacement is advis­ able when the car is operated in dusty areas or on
unpaved roads. Accumulated dirt restricts air flow,
reducing fuel
economy
and performance.

Fl-19.
REMOVAL
PROCEDURES

The
following paragraphs
give
the procedures for removing the major units of the Exhaust Emission

Control
System and the required equipment
needed.

Fl-20.
Air
Pump

Loosen
the air pump adjusting strap to facilitate

drive
belt removal. Remove the air pump air dis­
charge hose(s) and air filter attachment. Separate
the air pump from its mounting bracket. At time of installation, torque tighten the air pump mount­ing
bolts
to
30-40
lbs-ft. [4,15 a 5,53 kg-m.]. Adjust
the belt strand tension to
50-60
pounds on a belt
with previous service and
60-80
pounds on a new
belt.

Fl-21.
Anti-Backfire
Diverter Valve

The
anti-backfire diverter valve removal requires disconnecting the
hoses
and bracket to
engine
at­
taching screws.

Fl-22.
Air
Distribution
Manifold
and
Injection Tubes

In
order to remove the air distribution manifold
without bending the tubing, which could result in
fractures
or leakage, it is necessary to remove the
exhaust manifold as an assembly from the
engine.

After
the exhaust manifold assembly is removed
from
the
engine,
place the manifold in a vise and

loosen
the air distribution manifold
tube
retaining nuts at each cylinder exhaust port. Tap the injec­
tion
tubes
lightly to allow the air distribution mani­
fold to be pulled away partially from the exhaust manifold. The stainless steel injection
tubes
in the
exhaust manifold may have
become
partially fused
to the air distribution manifold and, therefore, may
require
application of heat to the joint in order to
separate. While applying heat to the joint, rotate
the injection
tubes
with pliers being careful not to
damage the
tubes
by applying excessive force.

At
time of installation, the air injection
tubes
must
be positioned into the exhaust manifold prior to
placing the exhaust manifold assembly on the en­ gine.

Note:
Two different length injection
tubes
are used.

The
shorter length injection
tubes
must be inserted into cylinders 1 and 4. 145

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

F2

14043

FIG.
F2-6—REPLACING VACUUM MOTOR ASSEMBLY

A—Drill
VW
Hole
B—Sensor
Unit
Replacement Position
1—
Motor
3—Sensor
Unit

2—
Spot
Welds
4—Retaining
Strap
•e.
Drill
a
%j
inch [2,78 mm.] hole in snorkel tube

at
point
"A"
as shown in Fig.
F2-6.
f.
Use the motor strap retainer and the
sheet
metal

screw
provided in the motor replacement kit to secure the retainer and motor to the snorkel tube.
g. Make sure the screw
does
not interfere with the
operation of the damper assembly. Shorten screw
if
required.

F2-9.
Replacement
of Air
Cleaner Sensor

a.
Remove two sensor retaining clips by
prying.
See

Fig.
F2-7.

b.
Pull
vacuum
hoses
from sensor.

c.
Note
carefully the installed position of the sensor so that you can install new sensor in same position.

Then
remove sensor.

d.
Install
sensor and gasket assembly in air cleaner

m
same position as noted in
step
c.
This
is to eliminate the possibility of interference with the air

filter
element.
e.
Install
sensor retaining
clip,
meanwhile support­
ing
sensor at B around the outside rim to prevent 14042

FIG.
F2-7—REPLACING SENSOR ASSEMBLY

1—Sensor
Retaining
Clip
damage to the temperature sensing spring. See

Fig.
F2-7.

f.
Reinstall
vacuum hoses.

F2-10.
AIR
PUMP
The
air injection pump is a positive displacement
vane type which is permanently lubricated and
requires
no periodic maintenance.

The
pump contains an integral relief valve which
controls the
air
supplied to the
engine
exhaust ports

during
high speed operation to limit maximum exhaust system temperatures.

F2-11.
AIR
FILTER
The
air injection system draws clean air from the
carburetor
air filter through an inlet hose, into the

air
pump and from the pump through two
outlets
(one for each cylinder head).

F2-12.
AIR
DELIVERY MANIFOLD

The
air delivery manifolds constructed of cold
rolled
steel with a zinc plating, distribute the air

from
the pump to each of the air delivery tubes in

a
uniform manner.

Two
check valves are included to prevent the
reverse
flow of exhaust
gases
to the pump should
the pump drive
fail.
This
reverse flow would dam­
age the air pump and connecting hose.

F2-13.
AIR
INJECTION TUBES
The
air injection tubes of stainless steel are in­ serted into machined
bosses
of the cylinder head.

The
tubes project into the exhaust ports directing
air
into the vicinity of the exhaust valve stem.

F2-14.
ANTI-BACKFIRE VALVE
The
anti-backfire valve is used to provide a "gulp" of air into the
engine
induction system during
rapid

throttle opening and subsequent closure.
During
rapid
throttle closure, the valve
opens
for approxi­
mately one (1) second and bleeds air into the
intake
manifold through a fitting in the carburetor.

Its
function is to bleed an adequate amount of

air
below the carburetor throttle plate to compen­ sate for the
overrich
fuel mixture normally inducted
into the combustion chamber during
rapid
throttle

closure.

Filtered
air from the pump is provided to the
anti-backfire
valve by means of a connecting hose.

An
exhaust system backfire
will
result if the valve

fails
to function properly.

F2-15.
ENGINE COMPONENTS
The
following item varies in design or specifications

from
those
on vehicles not equipped with the Ex­

haust
Emission
Control
System.

F2-16.
Carburetor

Check
carburetor number for proper application. Specifications are listed in this section.

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, lights and accessories off and the air cleaner in place.
Adjust
155