ACURA NSX 1991 Service Repair Manual

Fuel Pum p Resisto r
Troubleshootin g Flowchar t
— Engin e wil l no t start .
— Inspectio n o f fue l pum p resis -
tor.
Chec k th e operatio n o f th e PGM -
F I mai n relay :
1 . Disconnec t th e fue l pum p
resisto r 2 P connector .
2 . Measur e voltag e betwee n fue l
pum p resisto r connecto r ter -
mina l No . 2 an d bod y groun d
when th e ignitio n switc h i sfirs t turne d O N (II) .
I s ther e batter y voltage ?
(fo r 2 seconds )
Doe s th e engin e start ?
Chec k fo r a n ope n in th e wire :
1 . Tur n th e ignitio n switc h OFF .
2 . Disconnec t th e C48 6 (6P ) con -
necto r (locate d behin d th e
sea t bac k panels) .
3 . Measur e voltag e betwee n th e
C48 6 (6P ) connecto r termina l
No . 3 an d bod y groun d whe n
the ignitio n switc h i s firs tturne d ON .
I s ther e batter y voltage ?
(fo r 2 seconds ) FUE
L PUM P RESISTO R 2P CONNECTO R
WIR E SID E O F FEMAL E TERMINAL S
Inspec t th e PGM-F I mai n rela y
(se e pag e 11-143 ).
Replac e th e fue l pum p resistor .
C489 CONNECTO R (6P )
Inspec t th e fue l pum p (se e pag e
11-142 ).
TERMINA L SID E O F MAL E TERMINAL S
JUMPE
R WIR E
Chec k fo r a n ope n i n th e fue l
pum p resistor :
1 . Tur n th e ignitio n switc h OFF .
2 . Connec t fue l pum p resisto r
connecto r terminal s No . 1 an d
No. 2 wit h a jumpe r wire .3. Tur n th e ignitio n switc h t o
STAR T position .
Repai r ope n i n BLK/RE D wir e
betwee n th e fue l pum p resisto r
an d th e fue l pump .
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Fuel Suppl y Syste m
Fuel Pum p
Testin g
Do no t smok e durin g th e test . Kee p ope n
flam e awa y fro m you r wor k area .
I f yo u suspec t a proble m wit h th e fue l pump , chec k tha t
th e fue l pum p actuall y runs . Whe n it i s ON , yo u wil l hea r
som e nois e i f yo u hol d you r ea r t o th e fue l fil l por t wit h
th e fue l fil l ca p removed . Th e fue l pum p shoul d ru n fo r
tw o second s whe n th e ignitio n switc h i s firs t turne d on .
I f th e fue l pum p doe s no t mak e noise , chec k a s follows :
1 . Remov e th e bulkhea d panels .
2 . Disconnec t th e C48 6 (6P ) connecto r (locate d behin d
th e bulkhea d panels) .
CAUTION : B e sur e t o tur n th e ignitio n switc h OF F
befor e disconnectin g th e wires .
3 . Disconnec t th e PGM-F I mai n rela y connecto r an d
connec t th e No . 2 termina l an d No . 5 terminal * wit h
a jumpe r wire . * : 8 P connecto r
PGM-FI MAI N RELA Y CONNECTOR S
WIR E SID E O F FEMAL E TERMINAL S
4. Chec k tha t batter y voltag e i s availabl e a t th e fue l
pum p connecto r whe n th e ignitio n switc h i s turne d
O N (positiv e prob e t o th e No . 3 terminal , negativ e
prob e t o No . 6 termina l wire) .
C486 CONNECTO R (6P )
(BLK )
(BLK/YEL )
TERMINAL
SID E O F
MAL E TERMINAL S
If batter y voltag e i s available , replac e th e fue l
pump .
I f ther e i s n o voltage , chec k th e fue l pum p
groun d an d wir e harnes s (se e pag e 11-144 ).
Replacemen t
Do no t smok e whil e workin g o n fue l sys -
tem. Kee p ope n flame s awa y fro m you r wor k area .
1 . Remov e th e fue l tan k (se e pag e 11-147 ).
2 . Disconnec t th e connecto r fro m th e fue l pump .
3 . Remov e th e fue l pum p mountin g nuts .
4 . Remov e th e fue l pum p fro m th e fue l tank .
27 N- m (2. 8 kgf-m , 2 1 Ibf-ft )
5. 9 N- m (0. 6 kgf-m ,
4. 3 Ibf-ft )
FUE L PUM P FUE
L PUM P
BRACKE T
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PGM-FI Mai n Rela y
Descriptio n
Th e PGM-F I mai n rela y actuall y contain s tw o individua l
relays .
Th e rela y i s locate d behin d th e passenger' s sea t bac k
panel .
On e rela y i s energize d wheneve r th e ignitio n i s o n whic h
supplie s th e batter y voltag e t o th e ECM , powe r t o th e
fue l injectors , an d powe r fo r th e secon d relay .
Th e secon d rela y i s energize d fo r 2 second s whe n th e
ignitio n i s switche d on , an d whe n th e engin e i s runnin g
whic h supplie s powe r t o th e fue l pump . Rela
y Testin g
NOTE : I f th e ca r start s an d continue s t o run , th e PGM-F I
mai n rela y is OK .
1 . Remov e th e PGM-F I mai n relay .
2 . Attac h th e batter y positiv e termina l t o th e No . 3 *
termina l an d th e batter y negativ e termina l t o th e
No . 2 * termina l o f th e PGM-F I mai n relay . The n
chec k fo r continuit y betwee n th e No . 5 * termina l an d
No . 2 termina l o f th e PGM-F I mai n relay .
• I f ther e i s continuity , g o o n t o ste p 3 .
• I f ther e i s n o continuity , replac e th e rela y an d
retest .
3 . Attac h th e batter y positiv e termina l t o th e No . 4 ter -
mina l an d th e batter y negativ e termina l t o th e No .
7 * termina l o f th e PGM-F I mai n relay . The n chec k
tha t ther e i s continuit y betwee n th e No . 3 termina l
an d No . 1 termina l o f th e PGM-F I mai n relay .
• I f ther e is continuity , g o o n t o ste p 4 .
• I f ther e i s n o continuity , replac e th e rela y an d
retest .
4 . Attac h th e batter y positiv e termina l t o th e No . 1 ter -
mina l an d batter y negativ e termina l t o th e No . 2 *
termina l o f th e PGM-F I mai n relay . The n chec k tha t
ther e i s continuit y betwee n th e No . 5 * termina l an d
No . 2 termina l o f th e PGM-F I mai n relay .
• I f ther e i s continuity , th e rela y i s OK ;
I f th e fue l pum p stil l doe s no t work , g o t o
Harnes s Testin g in th e nex t column .
• I f ther e i s n o continuity , replac e th e rela y an d
retest .
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Fuel Suppl y Syste m
PGM-F I Mai n Rela y
Troubleshootin g
Is ther e continuity ?
Chec k fo r a n ope n o r shor t i n th e
wire :Measur e voltag e betwee n th e
PGM-F I mai n rela y 4 P connecto r
terminal No . 3 an d bod y ground .
Is ther e batter y voltage ?
Chec k fo r a n ope n o r shor t i n th e
wire :
1. Tur n th e ignitio n switc h O N (II) .2. Measur e voltag e betwee n th e
PGM-F I mai n rela y 8 P connec -
tor termina l No . 5 an d bod yground .
PGM-FI MAI N RELA Y 8 P CONNECTO R
WIR E SID E O F FEMAL E TERMINAL S
Repai r ope n i n th e wir e betwee n
th e PGM-F I mai n rela y an d G10 1
(locate d a t righ t middl e o fengine) .
PGM-FI MAI N RELA Y 4 P CONNECTO R
Replac e th e ACG(S ) (2 0 A )
fus e i n th e engin e compart -
men t fuse/rela y box .
Repai r ope n o r shor t i n th e
wir e betwee n th e PGM-F Imain rela y an d th e ACG(S )
(2 0 A ) fuse . WIR
E SID E O F FEMAL E TERMINAL S
I s ther e batter y voltage ?
(T o pag e 11-145 ) Replac
e th e No . 2 FUE L
PUMP , SR S 2 (1 5 A ) fus e i n
th e under-das h fus e box .
Repai r ope n o r shor t i n th e
wir e betwee n th e PGM-F Imain rela y an d th e No . 2 FUE L
PUMP , SR S 2 (1 5 A ) fuse .
Engin
e wil l no t start .
Inspectio n o f PGM-F I mai n
rela y an d rela y harness .
Chec k fo r a n ope n in th e wire :
1. Tur n th e ignitio n switc h OFF .2. Disconnec t th e PGM-F I mai n
rela y 4 P connecto r an d 8 P
connector .
3 . Chec k fo r continuit y betwee n
th e PGM-F I mai n rela y 8 P
connecto r termina l No . 7 an d
body ground .
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(From pag e 11-144 )
Chec k fo r a n ope n in th e wire :
Measur e voltag e betwee n th e
PGM-F I mai n rela y 4 P connecto r
termina l No . 4 an d bod y ground . PGM-F
I MAI N RELA Y 4 P CONNECTO R
I s ther e batter y voltage ? —
Replac e th e I G COI L (3 0 A )
fus e i n th e engin e compart -
men t fuse/rela y box .
— Repai r ope n o r shor t i n th e
wir e betwee n th e PGM-F I
mai n rela y an d th e I G COI L
(3 0 A ) fuse . WIR
E SID E O F FEMAL E TERMINAL S
Chec k fo r a n ope n o r shor t i n th e
wire :
1 . Tur n th e ignitio n switc h t o th e
STAR T (III ) position .
NOTE:• M/T : Clutc h peda l mus t b e
depressed .
• A/T : Transmissio n in
position .
2 . Measur e th e voltag e betwee n
th e PGM-F I mai n rela y 8 P con -
necto r termina l No . 3 an d
bod y ground . PGM-F
I MAI N RELA Y 8 P CONNECTO R
WIR E SID E O F FEMAL E TERMINAL S
I s ther e batter y voltage ? —
Replac e th e No . 7 STARTE R
SIGNA L (7. 5 A ) fus e i n th e
under-das h fus e box .
— Repai r ope n o r shor t i n th e
wir e betwee n th e PGM-F I
mai n rela y an d th e No . 7
STARTE R SIGNA L (7. 5 A ) fuse .
Chec k fo r a n ope n in th e wire :
1 . Tur n th e ignitio n switc h OFF .
2 . Disconnec t th e EC M connec -
to r A (2 6 P ) fro m th e ECM .
3 . Chec k fo r continuit y betwee n
th e PGM-F I mai n rela y 8 P
connecto r termina l No . 2 an d
EC M connecto r termina l A4 .
WIRE SID E O F FEMAL E TERMINAL S
I s ther e continuity ? Repai
r ope n i n th e wir e betwee n
th e EC M (A4 ) an d th e PGM-F I
mai n relay .
(T o pag e 11-146 )
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Fuel Suppl y Syste m
PGM-F I Mai n Rela y
(From pag e 11-145 )
Chec k fo r a n ope n in th e wire :
1 . Reconnec t th e EC M connecto r
A (26P) .2. Reconnec t th e PGM-F I mai n
rela y 4 P an d 8 P connectors .
3 . Tur n th e ignitio n switc h O N (II) .
4 . Measur e voltag e betwee n
EC M connecto r terminal s
A13, C1, an d A12 .
ECM CONNECTOR S
WIRE SID E O F FEMAL E TERMINAL S
I s ther e batter y voltage ? Repai
r ope n i n th e wir e
betwee n th e EC M (A13 , C D
an d th e PGM-F I mai n relay .
Replac e th e PGM-F I mai n
relay.
Chec k fo r a n ope n in th e ECM :
1 . Tur n th e ignitio n switc h OFF .
2 . Measur e voltag e betwee n
EC M connecto r terminal s A 4
an d A1 2 whe n th e ignitio n
switc h i s firs t turne d o n fo r
tw o seconds .
Is ther e 1. 0 V or less ?
Substitut e a known-goo d EC M
an d recheck . I f prescribe d volt -
ag e is no w available , replac e th e
origina l ECM .
Chec k th e PGM-F I mai n rela y
(se e pag e 11-143 ).
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Fuel Tan k
Replacemen t
Do no t smok e whil e workin g o n fue l system . Kee p ope n flam e awa y fro m you r wor k area .
Mak e sur e lift s ar e place d properl y (se e sectio n 1 ).
1 . Rais e th e car .
2. Remov e th e drai n bolt , an d drai n th e fue l int o a n approve d container .
3 . Remov e th e cente r ro d (se e sectio n 5 ).
4 . Disconnec t th e M/ T shif t cabl e an d M/ T clutc h cabl e o r A/ T shif t cabl e fro m th e transmissio n (se e sectio n 14 ).
5 . Remov e th e bulkhea d panel s (se e se ctio n 20 ) an d acces s panel .
6 . Disconnec t th e C48 6 (6P ) connector .
7 . Disconnec t th e hoses .
CAUTION : Whe n disconnectin g th e hoses , slid e bac k th e clamps , the n twis t hose s a s yo u pull , t o avoi d damagin g
them .
8 . Plac e a jack , o r othe r support , unde r th e tank .
9 . Remov e th e stra p bolt s an d nuts , an d le t th e strap s fal l free .
10 . Remov e th e fue l tank .
NOTE : Th e tan k ma y stic k o n th e undercoa t applie d t o it s mount . T o remove , carefull y pr y i t of f th e mount .
11 . Instal l a ne w washe r o n th e drai n bolt , the n instal l part s i n th e revers e orde r o f removal .
C486 CONNECTO R (6P )
ACCES S
PANE L
TAN K STRAP S FUE
L FILTE R
DRAI N BOL T
49 N- m (5. 0 kgf-m ,36 Ibf-ft )
LOCKNU T
2 1 N- m (2. 1 kgf-m ,
1 5 Ibf-ft )
MOUNTIN G BOL T38 N- m (3. 9 kgf-m , 2 8 Ibf-ft )WASHE
R
Replace .
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Intake Air System

System Description

The system supplies air for all engine needs. It consists of the intake air pipe, Air Cleaner (ACL), intake air duct, throttle

body, and intake manifold. A resonator in the intake air duct provides additional silencing as air is drawn into the system.

IAB CONTROL

SOLENOID VALVE

To No. 5 BACK-UP LIGHTS

ALTERNATOR TURN SIGNALS

(15 A) FUSE

IAB

CONTROL

DIAPHRAGM

IAB

CONTROL

VALVE
THROTTLE

VALVE
INTAKE

AIR DUCT
ACL
RESONATOR
VARIOUS

SENSORS

INTAKE

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Air Cleaner (ACL)

ACL Element Replacement

ACL HOUSING

COVER

ACL ELEMENT

Normal conditions:

Replace air cleaner element every

30,000 miles (48,000 km) or 24

months whichever comes first.

Severe conditions:

Clean air cleaner element every

15,000 miles (24,000 km) or 12

months and replace every 30,000

miles (48,000 km) or 24 months

whichever comes first.

ACL HOUSING

RESONATOR

INTAKE

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Intake Ai r Syste m
Throttl e Cabl e
Inspection/Adjustmen t
1 . Remov e th e accelerato r positio n senso r cover .
2. Chec k tha t th e throttl e cabl e operate s smoothl y wit h
no bindin g o r sticking . Repai r a s necessary .
3 . Chec k cabl e fre e pla y a t th e throttl e linkage . Cabl e
deflectio n shoul d b e 1 0 - 1 2 m m (0.3 9 - 0.4 7 in.) .
ACCELERATO RPOSITIONSENSOR COVE R
DEFLECTIO N10 - 1 2 m m(0.3 9 - 0.47 in. )
LOCKNU T
CABLE
BRACKE T
ADJUSTIN G NU T
4. I f deflectio n i s no t withi n specs , loose n th e locknut ,
tur n th e adjustin g nu t unti l th e deflectio n i s a s spec -
ifie d the n retighte n th e locknut . Installatio
n
1 . Rotat e th e throttl e linkag e counterclockwise , the n
instal l th e throttl e cabl e i n th e throttl e linkag e an d
instal l th e cabl e housin g i n th e cabl e bracket .
THROTTL E LINKAG E
CABLE
BRACKE T
INNERWIRE
LOCKNU TADJUSTIN GNUT
2. Hol d th e cabl e sheath , removin g al l slac k fro m th e
cable .
3. Tur n th e adjustin g nu t unti l i t i s 3 m m (0.1 2 in. )
awa y fro m th e cabl e bracket .
4 . Tighte n th e locknut . Th e cabl e deflectio n shoul d no w
b e 1 0 - 1 2 m m (0.3 9 - 0.4 7 in.) . I f not , se e inspection /
adjustment .
LOCKNUT9.8 N- m(1.0 kgf-m ,
7. 2 Ibf-ft )
ADJUSTIN GNUT
CABL EBRACKE T
3 m m(0.1 2 in. )
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