ACURA TL 1995 Service Repair Manual

Throttle Cable

Inspection/Adjustment

1. Start the engine. Hold the engine at 3,000 rpm with

no load (transmission in or position) until the

radiator fan comes on, then let it idle.

2. Check that the throttle cable operates smoothly with

no binding or sticking. Repair as necessary.

3. Check cable free play at the throttle linkage. Cable

deflection should be 10 - 12 mm (0.39 - 0.47 in.)

ADJUSTING NUT

CABLE

BRACKET

DEFLECTION

10-12
mm

(0.39
-
0.47 in.)

4. If deflection is not within specs, loosen the locknut,

turn the adjusting nut until the deflection is as spec-

ified, then retighten the locknut.

5. With the cable properly adjusted, check the throttle

valve to be sure it opens fully when you push the

accelerator pedal to the floor. Also check the throttle

valve to be sure it returns to the idle position whenev-

er you release the accelerator pedal.
Installation

1. Fully open the throttle valve, then install the throttle

cable in the throttle linkage and install the cable

housing in the cable bracket.

LOCKNUT
INNER CABLE

ADJUSTING

NUT

THROTTLE

LINKAGE

CABLE

BRACKET

2. Start the engine. Hold the engine at 3,000 rpm with

no load (transmission in or position) until the

radiator fan comes on, then let it idle.

3. Hold the cable sheath, removing all slack from the

cable.

4. Turn the adjusting nut until it is 3 mm (0.12 in.) away

from the cable bracket.

3 mm

(0.12 in.)

ADJUSTING

NUT
LOCKNUT

9.8 N-m

(1.0 kg-m,

7.2 Ibf-ft)

5.
CABLE

BRACKET

Tighten the locknut. The cable deflection should now

be 10 - 12 mm (0.39 - 0.47 in.). If not, see inspection/

adjustment.
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Intake Ai r Syste m
Throttl e Bod y
Descriptio n
The throttl e bod y i s a single-barre l side-draf t type . Th e
lowe r portio n o f th e throttl e valv e i s heate d b y engin e
coolan t fro m th e cylinde r head . Th e idl e adjustin g screw ,
whic h increases/decrease s bypas s air , an d th e Evapora -
tiv e Emissio n (EVAP ) Contro l Caniste r por t ar e locate d o n
the to p o f th e throttl e body .
THROTTL EPOSITION(TP)SENSO R
IDLE ADJUSTIN GSCREW
THROTTL E
VALV E
THROTTLE
STOPSCRE W
(non-adjustable )
Inspection
CAUTION : D o no t adjus t th e throttl e sto p screw . I t i s
prese t a t th e factory .
1 . Disconnec t th e vacuu m hos e (t o th e EVA P contro l
canister ) fro m th e to p o f th e throttl e body ; connec t
a vacuu m gaug e t o th e throttl e body .
2 . Star t th e engine . Hol d th e engine at 3,00 0 rp m wit h
no loa d (transmissio n i n ! o r position ) unti l th e
radiato r fa n come s on , the n le t i t idle .
VACUU M PUMP/GAUG EA973X - 04 1 - XXXX X
3. Allo w th e engin e t o idle , an d chec k tha t th e gaug e
indicate s n o vacuum .
If ther e i s vacuum , chec k th e throttl e cabl e (se e
pag e 11-135 ).
4 . Chec k tha t vacuu m is indicate d o n th e gaug e whe n
the throttl e is opene d slightl y fro m idle .
If th e gaug e indicate s n o vacuum , chec k th e throt -
tl e bod y port . I f th e throttl e bod y por t i s clogged ,
clea n i t wit h carbureto r cleaner .
5 . Sto p th e engine , an d chec k tha t th e throttl e cabl e
operates smoothly without bindin g o r sticking .
I f ther e ar e an y abnormalitie s i n th e abov e steps ,
check for .
— Excessiv e wea r o r pla y i n th e throttl e valv e shaft .
— Stick y o r bindin g throttl e leve r a t ful l close posi-
tion.
— Clearanc e betwee n throttl e sto p scre w an d throt -
tl e leve r a t ful l clos e position .
There shoul d b eno clearance .THROTTLE LEVE R
THROTTL ELEVER
THROTTL E STO P SCRE W(Non-adjustable )
Replace th e throttl e bod y i f ther e is excessiv e pla y i n th e
throttl e valv e shaf t o r i f th e shaf t i s bindin g o r sticking .
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Disassembly
with TCS : Remov e th e TC S contro l valv e (se e sectio n 19 ).
CRUIS E CONTRO L CABL E
CAUTION :
Th e throttl e sto p scre w is non-adjustable .
Afte r reassembly , adjus t th e throttl e cabl e (se e pag e 11-135 ) an d th e cruis e contro l cabl e (se e sectio n 23 ).
T PSENSO R
O-RING
IDLE ADJUSTIN GSCREW THROTTL
E
CABLE
22 N- m(2.2 kgf-m ,
1 6 Ibf-ft ) GASKE
T
Replace .
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Intake Ai r Syste m
Intake Ai r Bypas s (IAB ) Contro l Syste m
Descriptio n
Satisfactor y powe r performanc e is achieve d b y closin g an d openin g th e intak e ai r bypas s (IAB ) contro l valves . Hig h torqu e
a t lo w rp m is achieve d whe n th e valve s ar e closed , wherea s hig h powe r a t hig h rp m is achieve d whe n th e valve s ar e
opened .
INTAKE AI R BYPAS S (IAB ) LO W
CONTRO L SOLENOI D VALV E OF F
ENGIN E SPEE D IS ABOV E 3,35 0 rp m INTAK
E AI R BYPAS S (IAB ) HIG H
CONTRO L SOLENOI D VALV E OF F
ENGIN E SPEE D IS ABOV E 3,95 0 rp m
IAB CONTROLLOW VALVE : CLOSEDIAB CONTROLHIG H VALVE : CLOSE D IA
B CONTRO L
HIG H VALV E
IA B CONTRO L
HIG H DIAPHRAG M VALV E
IABCONTRO LLOW VALVE IAB CONTR OLLO WDIAPHRAGM VALVE
IAB CONTROLLOW VALVE : OPENIABCONTROLHIG H VALVE : CLOSE D IA
B CONTRO L
LO W VALVE : OPE N
IA B CONTRO L
HIG H VALVE : OPE N
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Troubleshooting Flowchar t
Inspectio n o f IA B Contro l Sys -tem.
No. 2 VACUU MHOSE
Chec k fo r vacuu m at idle :1. Star t engin e an d allo w it t oidle .2. Remov e No . 2 vacuu m hos efrom th e IA B lo w contro l dia -phrag m valv e an d connec t vacu -
u m gaug e to th e hose .
VACUU M PUMP /GAUG EA973X - 04 1 -XXXX X
Is ther e vacuum ?
Check fo r vacuu m at IA B vacuu m
tank :
Disconnec t th e No . 4 vacuu m
hos e o n IA B lo w contro l solenoi d
valv e an d connec t a vacuu m
gaug e t o th e hose .
IAB LO WCONTRO LDIAPHRAG MVALVE
Is ther e vacuum ? Repai
r th e blockag e o r vacuu m
lea k betwee n th e IA B vacuu m
tan k an d th e intak e manifold .
Chec k fo r a n ope n i n th e wir e
(IABCS 1 line) :
1. Tur n th e ignitio n switc h OFF .2. Disconnec t th e 4 P connecto r
fro m th e IA B contro l solenoi d
valve assy .3. Star t engin e an d allo w i t t oidle .4. Measur e voltag e betwee n 4 P
connecto r termina l No . 2 an d
No. 4 .
IA B CONTRO L SOLENOI D VALV E
ASSY . 4 P CONNECTO R (C203 )
Wir e sid e o f femal e terminal s
I s ther e batter y voltage ? Replac
e th e IA B lo w contro l sole -
noi d valve .
Chec k fo r a n ope n in th e wir e (IG 1
line) :
Measur e voltag e betwee n 4 P con -
necto r termina l No . 2 an d bod yground .
(To pag e 11-140 ) (To pag e 11-140 )
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Intake Ai r Syste m
Intake Ai r Bypas s (IAB ) Contro l Syste m (cont'd )
(From pag e 11-139 )
Chec k fo r vacuu m at idle :
Remov e No . 8 vacuu m hos e fro m
th e IA B hig h contro l diaphrag m
valv e an d connec t a vacuu m gaug e
t o th e hose .
I s ther e vacuum ?
(T o pag e 11-141 ) (Fro
m pag e 11-139 )
I s ther e batter y voltage ?
Chec k fo r a n ope n i n th e wir e
(IABCS 1 line) :
1. Tur n th e ignitio n switc h OFF .2. Chec k fo r continuit y betwee nPCM connecto r termina l A2 0and 4 P connecto r termina lNo. 4 .
Is ther e continuity ?
Substitut e a known-goo d PC M
an d recheck . I f sympto m goe s
away , replac e th e origina l PCM .
Chec k fo r vacuu m at IA B vacuu m
tank :
Disconnec t th e No . 4 vacuu m
hos e o n IA B lo w contro l solenoi d
valv e an d connec t a vacuu m
gaug e t o th e hose .
I s ther e vacuum ?
Chec k fo r a n ope n i n th e wir e
(IABCS 2 line) :
1. Tur n th e ignitio n switc h OFF .2. Disconnec t th e 4 P connecto r
fro m th e IA B contro l solenoi d
valv e assy .
3 . Star t engin e an d allo w i t t o
idle .4. Measur e voltag e betwee n 4 P
connecto r termina l No . 1 an d
No. 3 .
(T o pag e 11-141 ) Repai
r ope n in wir e betwee n th e
4 P connecto r an d No . 4 EC U
(PCM ) (1 5 A ) fus e i n th e under -
das h fuse/rela y box .
PC M CONNECTO R A (26P )
IAB CONTRO LSOLENOID VALV EASSY. 4 PCONNECTO R (C203 )
Wire sid e o f
femal e
terminal s
Repai r ope n i n wir e betwee n
PC M (A20 ) an d th e 4 P connector .
No . 8 VACUU M HOS E
IAB HIG H
CONTRO LDIAPHRAG MVALVE
VACUU M
PUMP/GAUG E
A973 X - 04 1 -
XXXX X
Repair th e blockag e o r vacuu m
lea k betwee n th e IA B vacuu m
tan k an d th e intak e manifold .
Wir e sid e o f femal e terminal s
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(From pag e 11-140 ) (From pag e 11-140 )
I s ther e batter y voltage ?
Chec k fo r a n ope n in th e wir e (IG 1
line) :Measur e voltag e betwee n 4 P con -
necto r termina l No . 1 an d bod y
ground .
I s ther e batter y voltage ?
Chec k fo r a n ope n i n th e wire
(IABCS 2 line) :
1 . Tur n th e ignitio n switc h OFF .
2 . Chec k fo r continuit y betwee n
PC M connecto r termina l A2 2
an d 4 P connecto r termina l
No. 3 .
Is ther e continuity ?
Chec k th e IA B Lo w Contro l Sole -
noi d Valve :
Disconnec t th e 4 P connecto r fro m
th e IA B contro l solenoi d valv e
assembly . Replac
e th e IA B hig h contro l
solenoi d valve .
IAB CONTRO L SOLENOI D VALV EASSY. 4 P CONNECTO R (C203 )
Wire sid e o f femal e
terminal s
Repai r ope n in wir e betwee n th e
4 P connecto r an d No . 4 EC U
(PCM ) (1 5 A ) o r (20A ) fus e in th e
under-das h fuse/rela y box .
PC M CONNECTO R A (26P )
Repai r ope n i n wir e betwee n
PC M (A22 ) an d th e 4 P connector .
I s ther e vacuum ? Replac
e th e IA B lo w contro l sole -
noi d valve .
(T o pag e 11-142 ) (To pag e 11-142 )
Substitut e a known-goo d PC Mand recheck . I f sympto m goe s
away , replac e th e origina l PCM .
I s ther e vacuum ?
Chec
k fo r vacuu m at 3,40 0 rpm :
1 . Rais e engin e spee d t o 3,40 0
rpm.2. Chec k fo r vacuu m a t No . 2
vacuu m hose .
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Intake Ai r Syste m
Intake Ai r Bypas s (IAB ) Contro l Syste m (cont'd )
(From pag e 11-141 )
(From pag e 11-141 )
PCM CONNECTO R A (26P )
Chec k fo r vacuu m at 4,00 0 rpm :
1 . Rais e engin e spee d t o 4,00 0
rpm.2. Chec k fo r vacuu m a t No . 8
vacuu m hose . Chec
k fo r a shor t i n th e wir e
(IABCS 1 line) :
1 . Tur n th e ignitio n switc h OFF .
2 . Disconnec t th e PC M connec -
to r A (26P ) fro m th e PCM .
3 . Chec k fo r continuit y betwee n
PC M connecto r termina l A2 0
an d bod y ground .
Is ther e continuity ?
Substitut e a known-goo d PC M
an d recheck . I f sympto m goe s
away , replac e th e origina l PCM .
I s ther e continuit y to ground ?
Substitut e a known-goo d PC M
an d recheck . I f sympto m goe s
away , replac e th e origina l PCM . Wir
e sid e o f femal e terminal s
Repai r shor t t o groun d a t wir e
betwee n PC M (A20 ) an d th e 4 Pconnector .
Replace th e IA B hig h contro l sole -noid valve .
Repai r shor t t o groun d a t wir e
betwee n PC M (A22 ) an d th e 4 P
connector .
Chec
k fo r a shor t i n th e wir e
(IABCS 2 line) :1. Tur n th e ignitio n switc h OFF .
2 . Disconnec t th e PC M connec -
to r A (26P ) for m th e PCM .
3 . Chec k fo r continuit y betwee n
PCM connecto r termina l A2 2and bod y ground .
IA
B contro l syste m is OK . I
s ther e vacuum ?
I
s ther e vacuum ? Chec
k th e IA B hig h Contro l Sole -
noi d Valve :
Disconnec t th e 4 P connecto r fro m
th e IA B contro l solenoi d valv e
assembly .
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Testing
Intake Ai r Bypas s (IAB ) Lo w Contro l Valv e
1 . Disconnec t th e No . 2 vacuu m hos e fro m th e vacu -
u m hos e manifold , an d attac h a vacuu m pum p to th e
vacuu m hos e manifold .
IAB LO WCONTRO L SOLENOI D VALV E
No. 2 VACUUM HOSE
2.
VACUU M PUMP /GAUG EA973X - 04 1 - XXXX X
Apply vacuu m an d verif y tha t th e IA B contro l dia -
phrag m valv e hold s vacuu m an d tha t a s th e vacuu m
i s applie d an d release d th e IA B contro l diaphrag m
valv e ro d move s i n an d out .
I f th e IA B contro l diaphrag m valv e doe s no t hol d
vacuu m o r th e IA B contro l diaphrag m valv e ro d
doe s no t mov e i n an d out , replac e th e IA B con -
tro l valv e an d retest . Intak
e Ai r Bypas s (IAB ) Hig h Contro l Valv e
1.Disconnec t th e No . 8 vacuu m hos e fro m th e vacu -
u m hos e manifold , an d attac h a vacuu m pum p t o
th e vacuu m hos e manifold .
IAB HIG H
CONTRO L SOLENOI D VALV E
No. 8 VACUU M HOS E
2.Appl y vacuu m an d verif y tha t th e IA B contro l
diaphrag m valv e hold s vacuu m an d tha t a s th e vac -
uu m is applie d an d release d th e IA B contro l dia -
phrag m valv e ro d move s in an d out .
I f th e IA B contro l diaphrag m valv e doe s no t hol d
vacuu m o r th e IA B contro l diaphrag m valv e ro d
doe s no t mov e i n an d out , replac e th e IA B con -
tro l valv e an d retest .
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Emission Contro l Syste m
Three Wa y Catalyti c Converte r (TWC )
Descriptio n
The Thre e Wa y Catalyti c Converte r (TWC ) i s use d t o conver t hydrocarbon s (HC) , carbo n monoxid e (CO) , an d oxide s o f
nitroge n (NOx ) i n th e exhaus t ga s to carbo n dioxid e (CO
2), dinitroge n (N2) an d wate r vapor .
SECONDAR Y HEATE D OXYGEN SENSOR (SENSO R 2 )
HOUSIN G
THREE WA YCATALYST SFRONT O F
VEHICL E
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