Carburetor Adiustments ...........,..,..,.,... 71 Choke

O-OUAD_FUEL SYSTEM 1+6I
CARIER THERMO-GIUAD@ CARBURETOR
INDEX
Page
71
73
14
74
Carburetor Adiustments ...........,..,..,.,...
Accelemtor Pump Stroke .. ... ... ........... ..
Choke Controf Lever Adjustment ...........,..
Choke Diaphragm Connector Rod . . . , . . , . , , , . .
Choke Unloader Adjustment (Wide Oper,
...,............
Fast ldle Cam Position Adjustment . . . ... .....
Fast ldle Speed Adiustment (On Vehicle) .. ,. .
dle Settine Procedure ................... -...
Secondary-Air Valve Opening .................
Secondary Air Valve Spring Tension . . ... ... . .
Kick)................
f
76
75
77
17
72
73
Pase
11
Secondary Throttle Linkage
Secondary Throttle Lockout
Solenoid Bowl Vent Valve .
Vacuum Kick Adjustment
Disassembling Carburetor
General Information
76
...,..,...............
Inspection and Reassembly
Service Diagnosis
Service Procedures
Special Service Tools
Specifications
75
65
66
90
CARBURETOR APPIICATION
Requirement
California
California
California
Canada
California
California
Federal/Canada
California
Federal/Canada
ua
Tornta
Federal
Transmission
Engine
Manual
318
Four
Four
Auiomatic
Automatic
Automatic
Four
Four
I\4anual
360
Automatic
360
l\lan ual
360
l\4anua
BBLS
Fou
r
I
Automatic
Autornatic
Auiomatic
Four
Four
Carburetor
Model Numbet
Cader
Cafter
Carter
Ca*er
Carter
Carter
TQ-9228S
TQ-9229S
TQ-9223S
TQ"9227S
TQ-9224S
TQ-9225S
Carter
Carter
Cader
Carter
Carter
TQ-9207S
TQ-9208S
TQ-9209S
TQ-9210S
TQ"9226S
GEN ERAL INFORMATION
The Carter Theimo-Quad@ carburetor is designed to
hetp reduce exhaust emissions and to permit the
maximum performance that high-output engines ale
capable of delivering. (Fig. 1).
This carburetor has a unique black main body or
fuel bowl of molded phenolic resin. This acts as a
very effective heat insulator. Fuel is kept cooler
(approximately 20 degrces F) than in all-metal carburetor designs.
The air horn houses the choke valve, the air valve
for the secondaries and its controls and acljustments,
the fuel inlet system (two floats and inlet neeilles and
seats), the complete accelerating pump system, pdmary boost venturi, vacuum controlleal step-up piston and roals, low and high speed fuel mete ng systems (secondary jets, fuel discharge nozzles and all
air bleeds and rest ctions) (Fig. 2). The primary jets
are in the main body.
The Thermo-Quad carburetor has rufque features
which require extra caution during all adjustments.
The vacuum kick diaphmgrn providles lwo lrparal6
funclions. It still provides for vacuum kick but it also
contrcls the secondary air valve- Because of the
separate nature o{ the two Iunctlons, tltro separate
but interelated adjustments are necessary and these
adjustments must be pe ormed in the proper sequence.
V(,.vu.n Port ldentifrcdtion (Flg, 3)
All Thermo-Quad carburetors used on vehicles
equipped with exhaust gas recirculation (EGR) $'iI
have a venturi vacuum port on the side of the car
buretor; this is the only vacuum port located in the
main body. A11 other vacuum supply ports are locatea
in the throttle body.
See "Emission Control System", Group 25, of ':r:
manual for detailed information.
Five conventional circuits are found in the TtE-:Quad carburetor:
(1) Float circuit
(2) Low-speed circuit (in the primary side
13\ High-speed circuit lpriDaly and se..:: r-
1442
TH
ERMO-qUAD_FUEL SYST
SECONDARY AIR
ADJUSTMENT SCREW
CHOKE VALVE
VALVE
IDLE MIXTURE
ADJUSTMENT
scREwS
FAST IDLE
ADJUSTMENI SCREW
TO PCV VALVE
CANISTER
PIJRGE PORI
DIVERTER
VALVE
PR]9]8A
ig. l -Carbu rct o I Assembly
(4) Pump circuit
containing a fuel cavity float assenbly and needle
(5) Choke circuit (consisting of linkag€s to operate
and seat assembly. The pdmary low-speed circuit
from a choke mechadism in the manilold cavitv).
plus prihary and secondary high,speed circuits are
supplied rrith luel taken from the Juel cavities in tle
fuel bowl.
f ha Ftoat Cir.uir (Fig. 4)
The purpose of the float circuit is lo maintain an
the f.ow-Speed qnd tdle Enri.hment Circuit
adequafe supply of liquid fuel at the proper, prede(Fis.5)
termined level in the bowl for use by the low-speed,
Fuel {or idle and early part throttle operation is
high-speed, pump and choke circuik.
Two separate float circuits are used, each circuit
t
CAN STER
PURGE
PORT
D]VERTER
VAIVE
\..1.7
\ .:,i7.
,
TO VAPOR CANISTER
Fig. z-C.Jrberetor Assembly
fop Viev
Fig, 3:-Vo.sum Porr
PRI'20A
td.ntifi.allon
TH ERMO"OUAD_FU
metered through the low-speed circuit which is lo'
cated on the piimary side only
Liquid gasoline enters the idle wells through the
marn meterng jets. Each low'speed jet has a calibmted odfice at its lover tip which measurcs the
amount of {uel lor iclle and early part throttle opera'
tion. T'he air by-pass passages, economizers and ialle
air bieeds are careJuliy calibrated and selve to breat
up the liquid Juel and mL,< it with air as it moves
through the passages to the idle ports and idle
adjustment screw ports. Tuming the idle adiustment
screws towaral their seats reduces the quantity of fuel
mixture supplied by the idle circuit.
The idle system is equipped with a rcstrictor in the
idle channel, located between the transfer slot and the
idle port, which limits the maximum attainable idle
mlxture.
tdle Enrichment System (Fig. 5)
The ourDose oI lhe idle enrichment syslem is to reduce c;ld ;ngine stalling by use of a metedng system
related to the baslc carburctor instead of the choke
The system enriches carburctor mixtures in the
idle and off idle area during that portion of vehicle
operation related to cold or semicold opemtjon
A small vacuum confrolled diaphragm mounted
near the top ol the carburetor controls idle system air.
when contml vacuum is applied to the diaphragm'
ialle system air ls reduced. Air losses within the idle
system strengthen the small vacuum signal and fuel
flows increase. As a result oI more luel and less air,
the fnel air mixtures enrich (fig. 5).
Vacuum signal to the carbur€tor diaphragm is contrclled by a thermal switch that senses engine coolant.
Cold engines have switches in an open conclition to
pass the vacuum signal to the carburetor diaphmgm
Dudng warm-up the switches close to eliminate vacu_
um signals and return carburetor metering to normal,
MECHANICALLY
OPERATED BOWL
VENT
SOME MODELS
EL
SYSTEM
14.63
lean levels. IA one type system. vehicles relt on this
engine coolant vacuum switch to control !d]€ system
enrichment duration.
In a second system, vehicles have srmilar coolant
vacuum srritches, but the switch ?eceifes its lacuum
signal from a solenoid valve operated b: an electric
timer. nnrichment dumtion is approximateil- 35 sec.
onds aJter the engine starts. TlIe thermal s\l'itch sill
prevent additional cycles of idle system enrichment
after the engine reaches a warm condition. but \\'hile
the engine is cold, each restart cycles another 35 seconds of enrichment.
Engines which have cooled below the switch open_
ing temperature vill benefit by havhg endched idle
aJter restart. Duration of the endchment will be con'
trolled as descfibed above Jor each type system.
Solenoid controlled systems have switches which
close at 150'F while others close at gS"F Switches
open approximately 12'F below closing temperatures
(these are approximate temperatures).
Circuits
the Hiqh-Spoed
'pa11
throltle and tull lhrottle engine
Fuel-lor
operation is ;upplied through the high-speed circtit,
which is divid€d into the pdmary high-speed circuit
and secondary high-speed ciicuit. These two cir'
cuit functions are described separately, as follo{s:
High Speed Circuir-Primqry Srde (FiE. 6).
Tn lhe primafy metering seclton. Ine t\\'o melerlng
rods are yoked to a single step_up piston which ddes
in a cylinder in the bowl cover casting. The primary
jets which work with the metering rods are located
in the plastic fuel bowl. The step_up piston has a lift
rod which extends down through a passage in the fuel
bowt into the throttle body. The bottom end of the
rod ddes on a lever operated by a cam on the pdmary
throttle shaft.
BY PASS 1pg6 41q 91g69
IDLE ENRICHMENT
VALVE ASSEMBIY
IDLE ENRICHMENT
AIR
INLET
OPERATING LEVER
NEEDLE AND
sEAI
ASSEMELY
-c: :'
lDLE
FUEL INLET FITIING
Pfl838
lig. 4-FIoa, Cir..rit
RESTRICTOR
MAIN
METER
IDLE ENRICI]MEN-
AIR BLEED
RESTR
CT:..
NG JET
trg. 5-low sP.sd
cits,-
1+64
ERMO-OUAD_FUEL SYSTEM
TH
ANTI.PERCOLATOR
VENI
PISTON LINK
MAIN
WELL
DI5CHARGE
NOZZLE
PASSAGE
METER NG
MECHANICAL
ROD
LIFT ROD
MA N
METER
NG
.JET
THROIILE VALVE
"O"
side of the carburetor which is opened by air velocity
thrcugh the secondary bores and clos€d by accurately-
adjusted spririg tension. A unique feature of this air
valve is its shape. The lower edge of the valve is
contouredl in such a manner that when air velocity
through the carburetor is high, and the lower edge oI
the air valve approaches the secondary nozzles, the
contoun act as venturi to increase air velocity at the
tips of the nozzles.
Air V.,tve Dcshpot (Dtdphrcgmt OPerdfton
(Fig,8)
In addition to the air-valve functions descdbed, an
air valve dashpot (or diaphragm) is used to further
control the ail valve. The operation of the dashpot
plus the contrcl restrictions and passages is as follows:
RING SEAL
Fig. 6.-+rimory High Sp€€d Circuii
In the low- and medium-speecl range, the cam anal
lilt the step-up piston and mete ng rcds in proportioa to the pdnary throttle valve opening. This
action provides positive mixture conhol.
The length of the step-up piston liJt rod is Jactoryadjusted wilh equipment not available in service.
Tampering with the setting will upset pedormance
and emission control
lever
Hrgh-Speed Circuit-Se.ondory Side (Fig. 7 )
Liquid fuel for the high-speed circuil in tbe second.
ary poltlon of the carbwetor is metered at the
secondary metering jets. There are no metering rods
in the secondary metering iets.
The main bleed tubes in the secondary side with
thefu calibrated perlomtions anal air bleeds, function
to plovide sensitively calibrated air-tuel mixtures in
AIR
response to etrgrne demadils.
A spring-loaded air valve is locateal in the seconalary
During primary throttle operatrrg condition (secondary valves not open) manifold pressure (vacuum)
is transmitted through the passages cornecting the
air valve diaphragm to the underside oI the carburet'
or flange. If the secondary valves arc opened Jrom
either a closed throttle or part throttle position oJ the
primary valves, the restrictions 'A', "B'and "C"
bleed ofr manifold pressure to the diaphragm thus
allowing the air valve to open at a rate that will
provide smooth secondary operation.
Restdctions "A" and "C" are sedes restrictions for
contrclling mte of pressure bleed off to the diaphragm with the secondary throttle valves closed.
Restdction "B" has an adaleal function: During steady,
extreme high-speeal opention (70 mph approx.) it is
possible that the secondary valves may be opened very
slightly. If the diaphragm was directly connected to
manifold vacuum at all times, the diaphragm might
BLEED
AIR VALVE DASHPOT
VENT
IUBE
BLEED
BAFFLE PLATE
SECONDARY
NO ]ET
METER
RESTRICT]ON
Fig,
PORI (RESTRIC-|'ON "BJ
SECONDARY THROTTLE VALVE
TO INTAKE MANIFOLD
SECONDARY THROTTLE
VALVE
"A"
D|SCHARGE NOZZLE
f-Second.Iry Higrt Speod cit uir
PFt86A
PF]878
Eig,
8-Alr Vdlv. O$hpot Op€tctiott
TH
ERMO.OUAD-FU EL
SYSTEM
14.65
amount of fuel necessalv- to insure smooth engine
operation upon acceleration at 1o\rer vehicle speeds.
PLUNGER SPRING
PUMP DIsCHARGE JET
PRIMARY THROTTLE VALVES
CHECK SFAT
Fig. 9 -A..sler.'l or
P
smp Cir.uit
pull the air valve to a closeal positiot causing an overrich mixture- Restdction "8" plevents this possibility
of over-richness. When the secondary is slightly
opened the restriction at "B" bleeds off a part of the
manifoldl vacuum to the diaphragm. The diaphragm
can then properly position the air valve for satisfac'
tory pedormance.
Accelerdtor Pump Cir.uit (Fig.9l
The a..elerating pump circuif. located in the pri.
mary side of the carburetor, proviales a measured
When the throttle is closed. the pump plunger
cllinder and fuel is dra{'r
into the pump cylinder through the intake check,
located at the bottom of the cllinder the a[scharge
check (needle) is seated at this tjme to Drelent air
frorn behg dlawn into the pump c\'linder
When the throttle js opened. th" pu p Dlunger
moves downward closing the intale check and forcing
luel out through the discharge passage. past lhe discharge check needle and out through the pump je,s
Ar higher spceds. pump drqcharge s _o lonsel
necessary to rnsure smooth acceleration. Therefore.
in order to prevent unnecessary plunger molelnent.
extemal pump linkage is so constructed that it travels
"over center" when the throttle is in the higher speed
positions, thus imparting just enough stroke to the
plunger to keep all passages filled with liquid fue1.
A plastic tube is used to connect the outlet opening
at the bottom of the pump cylhder with passage just
below the discharge check. Make suie this tube is not
damagecl or collapsed when ser-vicing the carburetor.
The spring in the pump cylinder, above the plunget
is used to remove all fuee play from the pump opemting linkage and insure an instant fuel discharge the
instant the throttle valves are cracked.
moves upwardl in the pump
SERVICE PROCEDURIS
DISASSEMBLING CARBURETOR
(1) Place carburetor assembly on repair stand
Tool C-3886. Repaf stand is used to protect throttle
valves from damage and to provide a suitable base
for working.
12) Remove tod retainers that hold throttle connec_
tor rod to accelerator pump arm and throtUe lever,
then remove rod from carburetor.
(3) Remove accelerator pump arm screw and
disengage tuom pump rod "S" lir*, (leave "S" link
connected to pump rod) then remove lever.
(4) Remove choke countershaft fast idle lever attaching screw whil€ holding lever. Disengage lever
ftom countershaft, then swing fast idle connector rod
at an arc until it can be disengaged from fast idle operating lever.
(5) Remove loil retainers and washer that holds
choke diaphragm connector rod to choke vacuum dia'
phragm and air valve 1€ver.
(6) Rernove rod retainer that holds choke connector rcd to choke counte$haft, then disetrgage rod
and swing rod at al} arc to disengage choke shaft
lever assembly.
(?) Remove step up piston cover plate attaching
screw anal cover plate, then remove step up piston
and link ass€mbly with step up rods. Remove step up
piston spring.
(B) Remove pump jet housing screw, housing with
gasket. Inveri carburetor and r€move discharge
check needl€.
(9) Remove 10 bowl cover screws, two of the bowl
cover screws are located between choke valve and
wall oJ bowl cover, Remove bowl cover and invert on
bench to protect floats.
Disossernbling Eowl Cover
(ll ReIao\e floal lAvpr prns and lifl out float as.
semblies. It is suggested that the float on the pump
side be marked so that goats can be reinstalled in
their respective positions.
\2' Remote l\ao nepdle valves from lheit resD...
tive seats, after marking one on pump side Jor :a:tiflcation. Using a wide blade screw driver. re5: :
needle \alve seals. Be sure each needle \a r : :+
tumed to its original seat at reassembh(3) Remove secondary metedng jets.
(41 Remove a..Aleralior I Lmp 1 :.
tic) and bowl cover gasket.
, :: -'€'
(5, Remove accclerator pump -
.4;
IH
ER
MO.SUAD_FUEL SYSTEM
-- :: luinp plunger assembly,
use a small roal placed
plunger shaft and tap tightl]'. with a
small hammer (Fig. 10). Use €are not to da'nage ptuhg.
er shaft hole in bowl cover. This should be done with
finger! under lower portion of pump cylinder in order
lo catch intake check seat, pump plunger and spring.
Check seat will be damaged when pump pt,rnger is
b€ing driven oui. Always install . new check seat
and plunger upon reassembly,
{61 U inspection shows plunger can be used agaitr,
place it in a container of clean mineral spjrits to Dre"
\ etr lcather Irom drying oui.
(71 Nole position of bowl venr actuatinE tever
and
arm spring (if so equipped) before removing retainer
.lip lfom lprer. {hen rpmove lcver {rom bowl rent
operating arm, Remo'Je grommet seal from operating
::. upper end
oJ
arm.
l8) Remove {uel intet fitting and gasket.
fhrojrle Body
(1) Remove atep-up actuating lever.
(2) Remove choke diaphragm and bracket assembly with hose and place to one side to be cleanecl as a
special item. Liquid cleaners may damage aliaphragm
material. Noter that the carburetor vacuum ffttine
hidpc a \er\ srall \acuum Dassage rcst.iclion. clpa;
(3) Remove plastic limiter caps from idle air mixture screws. Be sure to count nurnber of turns to seat
the scrervs (from stop). as the same number of turns
(trom seat) must be maintained at installation. Remove idle mixture screws and sprinss.
It is not advisable to remov; th; throttle shafts or
valves unless wear oi damage necessitates the instal-
VENT TUBE
lation of new pa s. During the manufacture of the
carburetor, the location of the idle transfer ports and
tbe idle discharge pods to the valve is carefulllr es_
tablished for one pa icular assembty. (Fig. 11).
ff new throttle sha{ts should be insialled in an otd
$'om body, it would be very untikely that the o ginal
rclationship oJ these ports to the valves would b-"
oitained. A very slight change in the polt rclation.
ship to the valves would adveNely affect normal carDuretor operation, between the speeds of curb idle to
30 miles p€r hour.
Moin Body
ll
Remove primarJ O rjng sea s ard dis.ard
Rnmove primary melering jels rFig. l2l
ra rs not re.essafy to rc^tova the bamo plate lrthe main body. (Do not imme$e main bodi), in clean
/2'
jng solvents for a proionged period of timel The
carburetor now has been alisassembled into three
main units, the air hotn, main body anrl throtUe bodr
and the.omponenl pafl. of ea.h d,sa.5c.nblpd as laj
as necessary for cleaning and inspection.
CLEAN IN G CARBURETOR PARTS
Refer to Gencral Information Section at front i :
Fuel System, for cleaning instructions.
INSPECTION AND REASSEMBLY
Check for cracks, waryage, str.jpped s.re!v thleai.
or damaged or Darred mating sudaces. on all maj,::
castings. The passages in the castings shoulal be fre€
of restrictions. Check the float assemblies lor damage
or any condilion rhat would impair lhese ilems lror
lurther ser\ ice. The throttle valvei choutd bp replaced
if the edges have been nicked, buned or da;aged
New valves may be installed. Be sure that the ch;ke
and throttle shaJts are not bent or scoreal. Replace
any broken or distoted spdngs. Replace all screws
and lockwasheN that show signs of stdpp€d threaals
or distortion
IDLE D SCHARGE
()
I
i
'
PIN PUNCH
rig. ro-Re.rovirg A..elerotor
Pump
Fig. I f-Ports
ir Retorion toth.ofite vo,tve,
TH
fhrot+te Body
If
necessary to replace throttle valves, remove
staking with a ffle. These screws are stakedl to prevent loosening anal cale is necessary to avoid breaking off in shaft.
(l) Remove screws that hold thrcttle valves to
throttle shaft.
(2) Slide damaged throttle valves out of borcs. It
should be noted at this tirne, that the numbered side
is on the bottom (or carburetor mounting flange
side) ahd opposite the vacuum port.
(3) Slide new throttle valves in position on throttle shaft, with the valve number on the bottom
(flange side) and opposite the vacuum port.
(4) Install new screws, but do not tighten. Be sure
fast idle speed adjusting screrv is backed out. Hold
valves in place rrith ffngers {fingers pressing on high
sidle of valves).
(5) Tap valves lightly jn this position, tighten
sctews securely. Stake screrts, Be sure to support
shaft wh€n staking screws. Operate the throttle
shaft, ftom closed to open position, it should operate
smoothly \rithout drag or sticking. I{old throttle
hody up to a strong light. The light visible around
the outer dliameter of the valves on the bores shoddl
be unitorm.
(6) Install secondary throttle valves in the same
manner as desc bed previously, The numb€rs
stamped on the valves must be toward the bottom
rear- For adjustment see Secondary Throttle Adiust-
ERMO-OUAD-FUEL
SYSTEM
I4.67
lightly against their seats with fingers. Back ofi the
number of turns counted at disassembly. Do not install limiler .aps at this time.
Choke Va.uom oidphtqgm (Also Air vdlve
Ddshpof)
(1) Inspect the vacuum diaphragm fitting io be
sure that the passage is not plugged \rith foreign
material. Leak test diaphragm to determine if it has
internal leaks. To do this, deprcss diaphragm stem.
fhen place finger over fitting to seal opening. Release
stem. If stem moves more than 1/16 inch in ten
seconds, leakage is excessive and assembly nust be
replaced.
(2) Position diaphragm and bracket assembly on
locating dowel on mounting surface. Install and tight'
en attaching screw.
(3) Inspect rubber hose for cracks before install.
ing on correct carburetor fitting- (Fitting next to
diaphragm bracket). Oo not connecl vocuum hose lo
diaphragm filting until afler va.uum kick adiustment
ha! been made. (See Carburetor Adjustments).
(4) Install step'up actuating lever with edg€s up
(Fig. 13).
(5) Install throttle body gasket and main body.
(6) Carefully install nertr primary "O" ling seals.
Be sure'O" ring seals are centered over holes in main
body.
(7) Install pdmary metering jets in floor of main
body and tighten securely.
ment,
(7) Install idle mixture screws and springs in the
throttle body. (The tapered portion must be straight
and smooth to insure having correct idle mixture
control-) Do not use a s€rev, driver. Tufn screws
PRIMARY METER
NG-
J,:;r,ELlJi',lO-<
MA N BODY
t-e)- UI
1
Sowl Cover
(1) Install secondary metering jets over bleecl hrbes
,n.l fidhtoh ca.,,relv ll'id 14\
(2) Position accelerator upper spdng (heavy) on
pump plunger with large diameter up (Fig- 15). Install
spring and olunger in c\linder. comprpssing sprirg
until rod extends through bowl cover, then install
pump "S" lirk to retaii assembly.
STEP UP
ACTUAIING
IEVER
S]EP UP
iio
^
':-),,,4)'.
'A'1
j
-..u
RING SEALS
Fis. t2-nemovins o.lnsrclting Ptimcry
cnd i|letet;ng Jetg
PRt 923
"O"
Ri'rgs
'{#
fig, t3-SteFUp Actuoting Lever Instdlldtion
1+68
THERMO.QUAD-FUEL SYSTEM
'
SECONDA
mise plunger and press downward. No fuel shoulal be
emitted frcm the discharge passage. Fuet leakage at
discharge passage indicates presence of dirt or a
damaged check needle. Clean again and install a new
check needle. netest for leakage_
(8)
U discharge check needle leaks after
test, attempt to reseat as follows:
above
(a) Insert a piece of
.;
TBLEED TUBE
(DO NOI REMOVO
Fig. t4-Removing or Irsrorring Se.ondory
tllerering Jers
(3) Position intake che.k seat with flanqe down otl
a clean frat surface.
(4) Position accelerator pump cylinder over the assembly, then apply firm hand pressure to bowl cover
to seat intake check seat in pump bore (Fig. 16).
(5) Install accelerator pump passage tube (plas_
I1CJ.
(6) Pour clean gasoline into clean container. aDproximately | 2 inch deep and caretully lower pump
housing into gasolire. Raise plunger anal press ligh y
on plunger shaft to expel air from pump passage.
(7) Install accelerator pump discharge check nee_
dle in discharge passage. Using a small clean rod,
hold discharge check needte firmly on its seat. Aqain
drill rod down on needle.
Lightly tap drill rod with a hammer to form a llew
seat. Remove and discard needle and install a new
one. Retest as descdbed previously. If service fix does
not correct the conditio!, a new carburetor will have
to be installed.
{br Install acceleralor pump jer hollsing. new
gasket and attaching screw. Tighten securely.
(c) Test operation, a clear straiqht strcam
should emit lrom each jet. If streams ar; not ident!
cal, a new accelerator pump jet housing should be
installed- After test, remove bowl cover andl accelera_
tor pump passage tube (plastic) from bowl cover.
(9) Install gaskets on {uel inlet needle seats. then
inslall in bowl cover. Tighten securely ,Be sure ea.h
needle seat and needle is reinstalled in its orisinal
posilion iI being reusedr.
(10) Place a new bowl cover to main body gasket in
in position on bowl cover, then slide right and left
floats into position in bowl cover, tlen install foar
fulcrum pins. Be sure marked float is in.talled on
pump 5ide o{ ihe bowl cover. Reler to Carburetor Acl_
justments for procedure.
(11) Install accelerator pump passage tube (plastic).
(12) Caution: Exam;ne primary,,O,, ring seats in
bottom of main body to be certain that thev are cenlered over holes (Fig. t2),
carefutty lower bowl
cover down on main body.'hen
The ,,O,, rings wifl hotd
the bowl .over up slightly untit screws ar6 insfatted.
*wr::
iig. | 5-A..eler.,or
Pump Assembty
Disossembled View
@-.fit.
cHecr sent
t5-rnsrdrlitrg Che.k Seor
PR1926
1
TH
lnsfall ren cover screws and tighren ro 50
pounds,
in two operations.
inch-
fli) Insiall fuel inlet fitting with a nerv gasket and
,Dghten
securelv.
(14) Engage pump rod .,S', link with
hole in accelcra,or pump arm. then position arm on ajr
horn and
lnsratr pump arm screw (Fig. 1?).
,15' Engage throttle connector rod vy,rth
hole in
.
throttle lever. jnstall other encl in accelerator pump
arm (center hole) and install roal retainers.
t::t",t."'"p up pisron spring in pisron cyiinder,
roroweo
"-,1t-9) Dy slep up rods and piston and
ory. Insratl cover plare and atta.hing screw.
"rrnTjghlen
"sr"a_
securely,
/i?) Engage choke conneclor
rod $rth hole in
.
cnohe shalt t€ver, lhen swing rod at an
ar. unlil rocl
can engage choke counte$haft. Install roal
retainer.
Engage last idle connector rod with slot
in fast
__(18)
idle operaling lever. then swing rod af an arc
until
rcver can engage.hoke countershalt
lwith choke
\alve hCd in open posilionl inslall Ieve, and ar'a.h'ng*s.reu. Tighlen spcurely whilp holilinq le\prr9r Engage choke diaphragm cornpctor rod
lo ajr
ratvp levAr. lhen in.lall washpr and rod
rerarrar. In-
s'all olhcr prd
1o choke va(uum diaphragm plunger
and install rod retain€
Choke Vdcuum Kick
. The .hokc diaphragm adjusrment conlro,s rhe ruel
oerlvery rvbilc the engine is ruon,ng tt posilions
lhe
cnoRe \alve withjn fhe air horn b) action
o[.he ]i1kage beiween the (hokA shaft and thp diaphragm
The
dlapnragm must bp energized to measure lne va{
uum
Klcl< aclJustmpnl Vacuum Car be supplipd
by an auxrrlalv vacuum source.
Choke Unloo,der (Wide Open KickJ
'| ne .hoke unloader
is a m_e.hanical device
to par-
ERMO-QUAD_FUEL
SYSTEM I4€9
lially open lhA .hoke valve at wide open
throl e. IL is
usco_ro etLmrnate .hokp cnri, nmenl
durirg cranking
Engines which have bsq, 6aa6.a .,
9-, ,1n.ungin"
srareo
0!_ excessive .hoke enrichmpnt
can be c,eared
Dy use"ol lhA unloader. Refer lo
carburetor adjustments lor adjusting procedure.
Secondary tfirottre lockout
,secondary rhroltlp oppralion is elimina.ed dunnS
the chokp cyde by use ot a tatch lriggered
bv-he f"si
tore
syslem.
Fds
dre Speed
rasl 'dle engine speed is used to overcorhe
colal engrne tfl( tron. slalls afler cold slarls
and stalls due to
.?rourelor.jcing. Make the adjustment
lo spec.6carons tf adiustment is necessary with leis than
3OO
miles (500
on the odomefer, the 3pecific.tion
.
.km) .
must be re.tuced 75 RpM. Make all adjustments
with
engine fully warmed up.
Refer to earburetor adjustrnent section for procedure.
F.rst fdre Cdrfi positio,
This adjustment rs jmportant to assure thal
the
speeos ot ea.h cam step occur at the proper time
ouring engine warm,up.
V c-.u u
m
Th
r
ottl e p ositi oner
s:T" r"gll BBD.arburerors are equipped wirh a
-,
rnrol
e positioner system which .onsists of an eleclronrc speed swtlch. an ere.lronically controllad !e.
cuum :olenoid \aive and a vacuum actuated
throtlle
positioner (Tig. 15).
J ..
. Thc sysrem s lun.ljon is to prevenl Llnbrrnpo
Irom enlprin8 lhe armo"phere .l -o"9h
:J:".:1391.,
rne \entc e s exhaLsl s)stem 1\nen lhp
engl. F 1., de.
celerated Jrom a high RpM. The elecrronLc speed
sriilch re.el!cs ignilion pul.es lrom the ile on
oa..
rFrminal .onnecrrng ro the ererLro-.: rs.
:Tlj":!l:.
ruron. conlrol unif. Il then senses u.hen (lp
e:a:1e
speed_e\ceeds 2000 RpM and ,ilo*. ,r."u.. .';;.
gize the throt e positioner. When thjs post!:.rer
ls
enersrzed. a throl',e stop i: prorideo .:t
.t .: in.
nt0tt the throltre lrom rerutning -o
Fig. l7-Pump Shclt',S,, tiDk,Drfdt
orio,
.r. . ._:
:o,e
posrllon \\'hen rhe lhrolLle i( fe:e"j C .
:e:,rn
,.o
ln: luu slop posilion .po: r or. r .:. _: .4o !aJ.
Dral,eq lor a s,ead) .tale e1g r( :o:.: .:
:;50 dpM.
As-(ne engrne is de(eleral-n!. :.. .l_ontc
speecl
when lhe "n. . .:,-d drops berow
:l],jn^:::*.
4uuu nFM and de.enefg.e ..-.- .nrortle positiOner
lnrs allo\s lhe 1l-rot'le ro j ..:. Lo the nofmal idle
stop posilion and lhF eJ .:. " ,. continue to
deceler.
ale to (Urb idje. Th. oo..-..0n positions the
throttle
q.e
Pp!
whenever
the
engire
!il,-,,ruy_"p:",17;0
deie'ctate,
tro ..., d,oo\e2000 RpI,l.oa.pe€o
Just below 2000 RplI Thrs proviales sufficient arr ilow
14"70
TH
ERMO"QUAD_FUEL SYS
through the engine to adequately alrlute the air-Iuel
mrxture,
It is essential that the idle speed adjustment be
made using only the idle speed screw on the carburetor. ldle 3el rpm adjustment musl nol b€ made using
the adjustment for the vacuum throttle positioner.
Improper adjustment ol the throttle positioner mat
result in excessive curb idle speed.
At completion of all idle set or throttle positioner
adjustments, engin€ must be cycled to a speed abole
2300 RPM manuallyto check for proper idle retum.
Diogrosis Procedure-v dcuufi f htoltre
Positiorer
(1) if vacuum throttle positioner aloes operate as
described in Step l under adjustment, the Iault\
component can be diagnosed as descdbed below.
(2) Check all wiring hamess and hose connections
1n sysrem,
(3) Vacuuln Actuaror Test-Apply vacuum from an
external source to the actuator. If actuator does not
operatej replace. If actuator operates, pinch ofi suppl] hose and observe actuator. If actuator remains in
operating position for one minute or more! unit is
satlsiactoly,
.1 Vacuum Solenoid Tesf-Apply vacuum from an
external source to manifold supply hose connection
or solenoid valve. Disconnect irting hamess from
solenoid and ground one terminal of solenoid. Conr,ect i2 volts to othel telminal and observe vacuum
actuator operation. If actuator does not cycle as 12
! olis is applied, replace solenoid. If operation is norna1. it will be necessary to replace the speed switch.
TH
I.
ERMO.QUAD_FUEL
SYSTEM
14"71
THERMO.QUAD CARBURETOR ADJUSTMENT
FLOAT SETTING ADJUSTMENT
29
l!
t32"
1./32")
TQ-9228S
TQ-92295
ra-9223S
rQ-9227S
21t32"
(! llJ2)
TQ-9224S
2.
TQ-9225S
TQ-9207S
TQ-9208S
TQ-9209S
TQ-9210S
IO-92265
SECON DARY THROTTLE LINKAGF
ADJUSTMENT
adjust link so
that primary and
secondary levers both
contact stops ai the
same time
TO-9228S To-q2)6s
TQ-9229S io-qrni{
TQ 9223s ro-ornpi
TQ-9227S ro-s2Oc<
TQ-9224S TQ_9210S
TQ-g225S
THRO]TLE VAIVES
]]ELD IN W DE
OPTN POS TION
BEND LINK
HERE TO
AD ]UST
BOTH STOPS MAK]NG
CONTACT AT SAME
(l) Invert
bowl cover.
(2) Install bowl cover gasket and with floats
resting
on seated needle the dimension of each float fTom
bowl cover gasket to botfom siale ol float should be as
indicated in "Specijications.l'
f3) li adiustmenl ls J e.assarj bend lever as shown
above. Never allow lip of Roar lever to be presled
against needle when adiusting.
the_secondary throttle Iinkage adiust,
--I9 :n::k"
ment.
hold fast idle lever jn curb iclle posilion and
in-
vArl c€rbulelor Slowly open primarJ rhrollip
val!es
rs possible to measure specified drstance
be,9:* edge oi primary vatve and rhF borF ,op:Y,".1
poslle lqre.port). Al Ihis measuremenl
.e.o da;y
valves should jusl start to open. If an adjuslmeni
i;
bjn9 secondary rhroute operalinS rod at
i"il.""?:
angt€ $jth Toot T-109-218. untit corrict adjusl.menl
urlrt 'l
nas Deen obtained. See Specjfications,
.I+12
TH
ERMO-qUAD_FUEL SYSTEM
3. SECONDARY AIR VALVE ALIGNMENT
aefer to
pr0ceciure
TQ-9228S
rQ-9229S
TQ-9223S
TQ-92275
TO-9224S
TQ-92255
TQ-92265
TQ-9207S
TQ-9208S
TQ-9209S
TQ-92r0S
4, SECONDARY AIR VALVE OPENING
ADJUSTMENT
3/8" TQ-9228S
7116" rQ-92075
TQ-929S
1t2
TQ"9208S
TQ-9209S
TQ-9210S
TO-92265
TQ-9223S
TQ-92275
TQ-9224S
TO-92255
AIR VALVE
(SHORT SIDE)
MEASURE
ALIGNMENT
HERE
1LON6 SrDE)
PRt 930
(1) With air valve in closed position the opening
betwee4 the air valve and air horn q'a]l at the long
side must be at its maximum and parallel with air
horn gasket surface-
(1) With air valve in wide open position, the opE:
ing of lhe air valve at rhe snori $de and air ; should be a6 shorvn in Specifications. The corner ::
air valve is notched for adjustment. Bend the corr::
with a pair of pliers to give prcper opening.
_'l
TH
TENSION ADJUSTMENT
2
TO-9225S 3 turns TQ-9228S
trom contact TQ-907S from contact TQ-92295
turns
TO-9208S
TQ-9209S
TQ-92235
T0-9210S
TQ-92245
14-13
ADJUSTMENT
at curb idle at secondary pick-up
5116"
TQ-9227S
2-5l8 turns
contact
SYSTEM
6. ACCELERATOR PUMP STROKE
5. SECONDARY AIR VALVE SPRING
trom
ERMO-QUAD_FUEL
TQ-92245 TQ,9225S
9164"
TQ-92235 TQ-9227S
lU 32"
31t64"
TQ-926S
3116"
TQ-9228S rQ-9229S
"rQ"9207S TO-9210S
23164"
rQ-9208S TQ-9226S
TQ-9209S
BEND THROTTLE
CONNECTOR ROD
PLIJNGER STEM
HERE TO ADJUS]
F RST STAGE
5PE' AL
:ao.
,...
SLOT
SCREWDRIVER
TURN COUNTER
cLocKwtsE
PRt 932
PUMP
(1) Hold air valve adjustment plug with screwdriver
when loosening lock plug or th€ spring may snap out
oI position requidng disassembly of the carburetor to
retrieve the spring.
(2) Loosen air valve lock plug and turn air valve
to position itseu to ivide open position.
(3) With a long screwdriver that will enrcr cenrer
of Tool C-4152 positioned on alr valve adjustment
plug, tum plug counter.lockwise until air valve contacts stop lighUy, test with ffnger, then an additional
tum (refer to specifications).
(4) Hold adjustment plug with screwdriver, and
tighten lock plug securely with Tool C-4152- Be sure
adjustment does not move. Check air valve for free
dom of movement.
BEND TANG HERE
LEVER
]O
ADJUS]
SECOND STAGE
is
Accelerator pump stroke
determined by
measurement oJ the accelerator pump plunger height
above the air horu surface
curb idle. Carburetols
with staged pump systems require a second height
.l
measurement at a throttle position related to a secondarJ throttle lockout. Adjust as follows.
FIRST STAGE
(l) Be sure throttle connector rod is in center hole
of three hole pump arm or in the inner hole of a two
hole arm,
(2) Use scale to measure height of accelerator
pump plunger stem (top).t curb idl€ (ignition ON
when equipped with a solenoid idle stop, not throttle
positioner), Pump measurements are shown in specifcations,
(3) Adjust plunger height by bending the throttle
connector tod in the proper area.
SECOND STAGE
11) when second stage specificatioDs ale indicated,
open choke then open throttle until secondary lockout latch is irr5l applied. Note that plunger travel
downward stops at that point.
(2) Use scale to measure to top of accelerator
pump plunger stem. See specifications.
(3) Adjust by bending proper tang.
)
14'14
TH
ERMO.QUAD_FUEL
SYSTEM-
7. CHOKE CONTROL LEVER ADJUSTMENT
3-3/8
(off vehicle)
TQ-9228S
TQ-9223S
TQ-9226S
TQ-9207S
TQ"9208S
ra-92275
TQ-9209S
TQ-9224S
TQ-9210S
TQ-9229S
TQ,9225S
8. CHOKE DIAPHRAGM CONNECTOR
ROD ADJUSTMENT
.040"
TQ,9228S
TQ-92295
TQ-92265
TQ,9207S
TQ-9208S
rQ-9223S
TQ-9227S
TQ-9209S
TQ-9224S
TQ.92IOS
TQ-9225S
ND LN
GAUGE
(APPLY LIGHT
TO ADJUS'I
DOWN
PRESSURE)
TOP OF
AIR
-.-Eii'eu'iero*
VALVE
l
pFtal3
BEND ROD rl_
,
HERE
(1J Place carburetor on flat object with surface
flush against bottom of flange and extending out under chokc control le'i'er.
(2) Close choke by pushing on choke lever with
throttle par y open.
r3) Mpasure vp i.al dislance from top of rod ho."
in control lever down to flat surface simulating carburetor bottom.
(4) Scale should read 3-3,,8 inches.
{5) ,Adjust by bending the link connectinq the two
chokc sharls a. indicaled
IF CHOKE CONTROL LEVER ADJUSTMENT IS
CHANGED THE VACUUM KICK, FAST IDLE CAM
POSITION AND CHOKE UNLOADER ADJUST.
MENTS MUST ALSO BE RE5ET.
TO A
f-
C)
(1) Be sure diapbragm is securety mounteil on
carburetor. Apply a vacuum of 15 o! more inches of
Hg to diaphragm to fully depress diaphragm stem.
12) Wilh light openjng pressure on air vahe adjust
connector rod to give specified clearance between air
vslve and stop.
IF CHOKE DIAPHRAGM CONNECTOR ROD AD.
JUSTMENT IS CHANGED THE VACUUM KICK
ADJUSTMENT MUST ALSO BE RESET
R'{O.qUAD_FUEL SYSTEM
9. CHOKE VACUUM KICK ADJUSTMENT
.100" TQ-9228S TQ-9224S .150" TQ-9207S
TQ-9225S
Ta,9226S
TQ-9227S
TO-9229S
TQ-9223S
TQ-9208S
TQ-9209S
TQ-9210S
14.15
'I(|. FAST IDLE CAM POSITION ADJUSTMENT
rQ-9229S
rQ-9226S
rQ-9207S
rQ-9223S
TQ,9227S
TQ-9224S
TO-9208S
TQ-9209S
TQ-9210S
TQ-9228S
.100"
measure at the lowest
edge of the choke valve
(throttle lever side)
TQ-9225S
measure atthe lowest edge of the
choke valve (throttle lever side).
GAUGE
L
].-
NG
CHT
FRES5URE
'LOs
ON
F):i
CAM
JDLE
LEVER
ADJL]5TING
TO VACUUM
SOURCE
CLOs
NG PRESsURE
.,
PPIA]5
J'wlsqee)<_--.{\---=_ffriP JsK
-A,
(1) OF vehi.le, using an auxiliary vacuum source,
disconnect vacuum hose from calburetor and connect
it to hose from vacuum supply with a small length of
tube to act as a fitting. Removal of hose from dia'
phmgm may require forc€s which could bend the dia_
phragm bracket. Be sure diaphragm i5 securely
mounted on .arburetor. Apply 15 inches oJ vacuum
to the diaphragm.
(2) Insert specified gauge between long side (lower
edge) oI choke valve and the air hom wall at a point
close to the outboard end of the gauging area. See
Specifications. Apply sufticienl closing pressure on
choke control lever lo provide a minimum choke
valve opening withoul distorlion of choke linkage.
Note that only this system rotates a spring conn€cting
the control lever to an adiustment lever. The correct
stops must be in contact lor proper measurement of
vacuum kick adjustment.
(3) Adiustmenr will be necessary if slight drag is
not obtained as gauge is b€ing removod. Bend the
tang indicated in to change contact \trith end of dia_
phragm rod. Do nol 6diu5t diaphragm rod. Adjust
tang carelully with a fwisting force on screwdriver(4) With vacuum applied to diaphragm choke
Valve Should Move Freely between open and adjust_
ed positions, If movement is not free, examine sys
tem for misalignment ol interlerences and conect.
Repeat adjustment if necessary.
f5) Reinstall vacuum hose on conect carburetor
fittins.
etu
srEP oF cAM
lD
l
r(
SECOND I']lGHESI
-(/
tD E
ADJUST NG
SCREW
1
\-zil
aD.J.l
PRl936
(1J With fast idle speed adjusting screw contacting
second highest speed step on fast idle cam, move
choke valve towards closed position vrith light pressure on fast idle contrcl lever.
(2) Insert specified gauge (see Specifications) be"
tween choke valve and wall of air hom. An aaljustment will be necessary iJ a slight drag is not obtained
as gauge is being removed.
If
(3)
an adjustment is necessary, bend fast idle
connector rod at angle until co$ect valve opening has
been obtained. {Use Tool T-109-2131.
FAST IDLE CAM POSITION ADJUSTMENT
IF
IS CHANGED THE CHOKE UNLOADER AND sEC.
ONDARY THROTTLE LOCKOUT ADJUSTMENTS
MUST BE RESET.
t
F
I+-76
THERMO-QUAD_FU EL SYSTEM
11. CHOXE UNLOADER ADJUSTMENT
(WIDE OPEN KICK)
.500"
.310"
measure at the lowest
edge of the choke valve
(throttle lever side)
12. SECONDARY THROTTLE LOCKOUT
ADJUSTMENT
TQ-9228S
rQ-92235
rQ-92295
TQ"9227S
TQ-9208S
TQ-9209S
TQ-9210S
TQ-9207S
TQ-9224S
TQ-922sS
TQ-9226S
.060"-.090"
TQ-928S
TQ-9229S
TQ-9223S
TQ-92275
TQ-9224S
TQ-9225S
TO-9226S
TQ-9207S
TQ-9208S
TQ"9209S
TQ-9210S
CIOS NG PRESsUR:
TANG
ADJUST
BEND
\
pRt
g:-
(1) Hold throttle valves in wide open position. Ir.
sert speciffed gauge betweetr long side (lower edge
oI choke valve and inner wall of air hom. See Speci:,
cauons.
(2) With fiIrger lightly prcssing against carn conlr.l
lever, a slight drag should be lelt as gauge is be:!:withdrawn. If ne!:essary, adjust by bending tang o:
fast idle lever until colTect opening has been ac,
tained.
111
Move fast ialle control lever to open choke posi-
2l Measure clearance between lockout lever and
::op. It should be as shown in specifications.
3l Bend fang on fast idl€ contrcl lever to provide
:roper crearance.
RMO.QUAD-FU EL
13. IDLE SETTING PROCEDURES
TQ-9228S
TQ-9229S
TQ-9223S
TQ-9227S
TQ"9224S
TQ-9225S
TQ-9226S
TQ"9207S
TO-9208S
TQ-9209S
TQ,9210S
Reler to Section 25-Emission Control System
for correct procedure.
SYSTEM I+11
14. FAST IDLE SPEED ADJUSTI\4ENT
1600
RPM
TO-9228S
TQ-9229S
TQ-9223S
TQ-9227S
TQ-92245
1750
RPi\l
TQ-9225S
TQ 9207S
TQ,9208S
TO-920!S
TQ.9210S
TQ-9226S
(Less than 300 miles (500 km),75 RPM less)
On a new vchi.le (under 300 miles) (500 kn), all
6peed 3ellings musl be reduced 75 RPM.
FAST IDLE SCREIV
ON
SECON
SHOULDER OF FIRS'i
STEP
(1) Remove ail cleaner.
(2) With engine ofi, transmission in NEUTRAL and
parking brake set, open throttle and close choke.
(3) Ciose throt e to place fast idle speed screw on
highest speed step.
(4) Move fast idle speed screw until scre\r drops to
second highest speed step.
(5) Start engine and determine stabilized speed.
Turn {ast idle speed screw to obtain speed listed in
specifications.
(6) Stopping engin€ between adjustments is not
necessary. However, reposition speed screw on cam
after each speed adjustment to provide correct
throttle ciosing torque-
.!+78
TH ERMO-QUAD_FU
EL SYSTEM
15. SOLENOID BOWL VENT VALVE
I6.
IDLE ENRICHMENT VALVE
refer to
illustration
refer to
ptocedure
TQ-9228S
TQ-9229S
TQ.9223S
TQ-9227S
TQ-92245
TQ-9225S
rQ-9226S
TQ,9207S
TQ-9208S
TQ-92095
rQ,9210S
APPTY ]5 ]NCHES OF VACUUM
DLE ENRICHMENT
VAIVE ASSEMSLY
CHAMBER VENT:D
TO FUEL 8O\!'L
SOLENO D
VACUUM SOURCE
CAN
STEF
(1) Remove air cleaner.
i2) Disconnect hose to solenoid bolil !eri :r..
phragm.
(3) Connect auxiliary vacuum source and ob:a:.a
valve mo\emenl. oy lool rg dow| lhrou.-'h _b. : :
horn vent tube. lvhen 15 or more inches of merci:. :!
applied.
(4) Tum ignition switch on and disconnect au\rl::::
vacuum source, Valve should remair! in the iiar!:.
position unlil ignition switch is turned ofi.
(5) If the valve does not move when vacuum is a:plied lo diaphragm. the diaphragm rs Ieaking
:'
"-d
If
the
valve
not
re.
must
be
replaced.
does
assembiy
main in the down position when the igrition s\ritch r:
tum€d on and the vacuum source is removed 1ie
solenoid or related wiring is defective.
(6) Install air cleaner.
[t.
1) Warm engine
to normal operating tempera-
2J Remove air cleaner cover to provide access to
:ar0urercr,
3l Disconnect hose to idle enlichment system dia-:hragm at plastic connector (connector must be re,
:roled from carburetor hose because it is a filtered
rleeC which will intedere with test).
-11 Start engine and place fast idle speed screw on
:;tiing step o{ fast idle cam.
i Connect 3 or 4 feet of hose to the enrichment
iraDhragm hose with suitable connector.
6t Apply vacuum to other end oJ hose (use auxilr:rJ racuum Source) and check for engine speed
::ange.If speed can be controlled by vacuum, the dia::-ragm and air valve ar€ operating satisfactory. If
i-. e ed cannot be controlled proceed to next step.
;r Place finger or other plug over air inlet passage
::il listen {or engine speed change. I{ speed can be
..rr,1rolled, the diaphragm is leaking or the air valve is
:lrcli open. If speed cannot be controlled, the air
lalte is stuck closed. In either case, clean the air
'. ah e and repeat step 6. I{ speeal control is still absent,
::]]lace the diaphragm.
RMO.qUAD-FUEL SYSTEM I+79
I7. VACUUM TH ROTTLE
POSITIONER
ADJUSTMENT
(1) Start engine and allow to idle in Neutrai, then
accelerate engine to a speed above 2000 RPM and
verify that vacuum positionei unit operates and can
withstand a hand applied load il1 the operating position. If operation is not proper, detemine cause of
failure before proceeding, using diagnosis prccedurc.
(2) If unit operates properly as described above,
adjust to operate at specified speed using the Jollowing procedure:
(3) Accelerate engine manually to 2000 RPM.
(4) Loosen positioner adjustment lock nut and rotate complete vacuun'! positioner assembly until positioner just contacts throttle lever.
(5) Release thmttle, then slowly adjust positioner
to decrease eigine speed until a sudalen drop in
speed occurs (over 1000 RPM). At this point, continue
adjusting vacuum positioner in decreasing direction
1/4 additional tum and tighten lock nut. Accelerate
engine manually to approximately 2300 RPM and re,
Iease throttle, engine should relurn to normal idle.
This comDletes the adiustment.