ACURA NSX 1997 Service Repair Manual

Cylinder Head s
Remova l
Engine remova l i s no t require d fo r thi s procedure .
Mak e sur e jack s an d safet y stand s ar e
place d properl y an d hois t bracket s ar e attache d t o cor -
rec t position s o n th e engine .
CAUTION :
• Us e a fende r cove r (specia l tool ) t o avoi d damagin g
painte d surfaces .
• Unplu g th e wirin g connector s carefull y whil e holdin g
the connecto r portio n to avoi d damage .
• T o avoi d damagin g th e cylinde r heads , wai t unti l th e
engin e coolan t temperatur e drop s belo w 100° F
(3 8° C) befor e loosenin g th e retainin g bolts .
• D o no t ope n th e engin e cove r whe n th e roo f pane l i s
store d (NSX- T ope n top) .
NOTE :
• Unspecifie d item s ar e common .
• Mar k al l wirin g an d hose s t o avoi d misconnection .
Also , b e sur e tha t the y d o no t contac t othe r wirin g o r
hose s o r interfer e wit h othe r parts .
• Inspec t th e timin g bel t befor e removin g th e cylinde r
head .
• Tur n th e crankshaf t pulle y s o tha t th e No . 1 pisto n i s
a t to p dea d cente r (se e pag e 6-19 ).
1 . Disconnec t th e negativ e termina l fro m th e battery .
2 . Remov e th e expansio n tan k cap .
Us e car e whe n removin g th e expan -
sio n tan k ca p t o avoi d scaldin g b y engin e coolan t
o r steam .
3 . Rais e th e car , the n remov e th e righ t rea r wheel/tire .
4 . Drai n th e engine coolan t (se e pag e 10-5 ). 5
. Remov e th e fron t exhaus t manifol d (M/T) .
-1 . Remov e th e cente r ro d assembl y an d unde r
guar d (se e pag e 5-7 ).
-2 . Remov e th e rea r bea m ro d assembl y (se e pag e
5-8).
-3 . Remov e th e fron t engin e mount , the n remov e
th e fron t bea m (se e pag e 5-8 ).
-4 . Remov e th e fron t mount .
FRONT ENGIN EMOUNT
-5. Disconnec t th e fron t primar y heate d oxyge n
senso r (fron t primar y HO2S ) connecto r an d
fron t secondar y heate d oxyge n senso r (fron t
secondar y HO2S ) connector , the n remov e th e
fron t exhaus t manifol d an d fron t thre e wa y cat -
alytic converte r (TWC ) assembly .
COVERGASKE TReplace .FRONT SECONDAR Y
HO2 S CONNECTO R
Replace.
FRONT EXHAUS T
MANIFOL D AN D
FRON T TW C
ASSEMBL Y FRON
T PRIMAR Y
HO2 S CONNECTO R
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6. Remov e th e rea r exhaus t manifol d (M/T) .
-1 . Remov e th e muffle r (se e pag e 5-9 ).
-2 . Remov e th e rea r bea m ro d B .
REA R BEA MROD B
-3 . Disconnec t th e rea r secondar y heate d oxyge n
senso r (rea r secondar y HO2S ) connector , the n
remov e th e rea r TWC .
-4 . Remov e th e rea r exhaus t manifol d covers .
-5 . Disconnec t th e rea r primar y heate d oxyge n
senso r (rea r primar y HO2S ) connector , the n
remov e th e rea r exhaus t manifold .
GASKETReplace .
REAR EXHAUS T
MANIFOL D
REAR PRIMAR YHO2SCONNECTO R
REAR TW C
REAR SECONDAR YHO2S CONNECTO R
7. Remov e th e engin e unde r guard , the n remov e th e
fron t exhaus t pip e A (A/T) .
GASKET SReplace.
FRONT EXHAUS TPIPE A
REA REXHAUS TPIPE A
GASKET SReplace.
9. Remov e th e engin e oi l coole r bas e assembl y (se e
pag e 6-15 ).
10 . Lowe r th e car .
11 . Remov e th e stru t brac e (se e pag e 5-3 ).
(cont'd)
8
. Remov e th e rea r exhaus t pip e A (A/T) .
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Cylinder Head s
Remova l (cont'd )
12. Remov e th e engin e cove r sta y fro m th e stru t brace ,
the n se t th e engine cover sta y betwee n th e engine
cove r an d rea r hatc h latc h (NSX- T ope n top) .
CAUTION : Us e a sho p towe l t o avoi d damagin g
painte d surfaces .
SHOPTOWE L
13. Reliev e fue l pressur e (se e sectio n 11 ).
D o no t smok e whil e workin g o n fue l
system ; kee p ope n flam e o r spar k awa y fro m wor k
area . Drai n fue l onl y int o a n approve d container .
14 . Remov e th e fue l fee d pip e an d fue l retur n hos e (se e
pag e 5-5 ).
15 . Remov e th e evaporativ e emissio n (EVAP ) contro l
caniste r hos e an d brak e booste r vacuu m hos e (se e
pag e 5-5 ).
16 . Disconnec t th e breathe r pip e an d vacuu m hose , the n
remov e th e ai r cleane r housing .
AIR CLEANE RHOUSING
BREATHE RPIPE
17. Remov e th e hoses , the n remov e th e expansio n tan k
(se e pag e 5-5 ).
18 . Remov e th e radiato r hose s an d heate r hos e (se e
pag e 5-6 ).
19 . Disconnec t th e tw o connectors , the n remov e th e
contro l bo x (se e pag e 5-6 ).
20 . Remov e th e intak e manifol d plat e an d to p cover .
INTAK E MANIFOL DPLATE
TO P COVE R
21. Remov e th e fue l injecto r covers .
FUEL INJECTO R
COVE R
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22. Remove the breather hose, positive Crankcase venti-

lation (PCV) hose and vacuum hose.

VACUUM HOSE

PCV HOSE
BREATHER

HOSE

23. Remove the ignition coil cover and harness cover.

IGNITION COIL

COVER
24. Remove the water bypass hoses.

WATER BYPASS

HOSES

25. Remove the harness covers and ground cables from

the intake manifold.

GROUND CABLE

GROUND CABLE

(cont'd)ProCarManuals.com

Cylinder Head s
Remova l (cont'd )
26. Remov e th e engin e wir e harnes s connector s an d
wir e harnes s clamp s fro m th e cylinde r hea d an d
intak e manifold .
• Si x injecto r connector s
• Intak e ai r temperatur e (IAT ) senso r connecto r
• CKP/CY P senso r connecto r
• Heate d oxyge n senso r (HO2S ) connector s
• Ignitio n contro l modul e (ICM ) connector s
• Engin e coolan t temperatur e (ECT ) senso r connec -
tor
• Coolan t temperatur e gaug e sendin g uni t connec -
tor
• Radiato r fa n contro l senso r connecto r
• Exhaust gas recirculatio n (EGR ) valv e lift senso r
connecto r
• Throttl e positio n senso r connecto r
• Engin e oi l pressur e gaug e sendin g uni t connecto r
• Knoc k senso r connecto r
• VTE C solenoi d valv e connector s
• VTE C pressur e switc h connector s
• Engin e oi l pressur e switc h connecto r
• Alternato r connecto r
• Alternato r termina l
• Throttl e bod y 6 P connecto r
27 . Remov e th e ignitio n coil s an d connector .
28 . Remov e th e EG R pip e an d intak e manifol d assem -
bly.
GASKET SReplace.
INTAKEMANIFOL DASSEMBL Y
GASKETReplace .
29. Loose n th e adjustin g nu t an d idle r pulle y cente r nut ,
the n remov e th e ai r conditionin g compresso r bel t
(se e pag e 6-17 ).
30 . Remov e th e cover , adjustin g bolt , mountin g bol t
an d mountin g nut , the n remov e th e alternato r bel t
an d alternator .
COVER
ADJUSTIN GBOLT
MOUNTIN G BOL T
MOUNTIN G NU T
ALTERNATO RBELT
31. Disconnec t th e knoc k senso r connector , the n remov e
th e wir e holder .
KNOCK SENSO RWIRE HOLDE R
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32. Remov e th e wate r passage .
O-RINGSReplace .
CONNECTIN G PIP E
WATE R PASSAG E
33. Remov e th e cylinde r hea d covers .
CYLINDE R HEA DCOVE R
WASHE R
34. Remov e th e alternato r bracke t stiffene r (se e pag e 6-16 ).
35 . Remov e th e alternato r bracket .
ALTERNATO RBRACKET
36. Remov e th e timin g bel t (se e pag e 6-15 ).
37 . Remov e th e camshaf t pulleys .
RETAININ GBOLTSCAMSHAF T PULLEY S
(cont'd)
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Cylinder Head s
Remova l (cont'd )
38. Remov e th e fron t an d rea r bac k covers .
REAR BAC KCOVE R
RUBBE R SEAL S
FRON T BAC K
COVE R
39. Loose n th e rocke r ar m locknut s an d th e adjustin g
screws .
40 . Remov e th e camshaf t holde r plates , camshaf t holder s
an d camshafts .
FRONT INTAK ECAMSHAF T CAMSHAF
T HOLDE R
PLATES
FRONT EXHAUS T
CAMSHAF T
OI L SEAL S
Replace .
41. Remov e th e cylinde r hea d bolts , the n remov e th e
cylinde r head .
CAUTION : T o preven t warpage , unscre w th e bolt s
i n sequenc e 1/ 3 tur n a t a time ; repea t th e sequenc e
unti l al l bolt s ar e loosened .
CYLINDE R HEA D BOLT S LOOSENIN G SEQUENC E
NOTE : Separat e th e cylinde r hea d fro m th e bloc k
with a fla t blad e screwdrive r a s shown .
42. Remov e th e fron t an d rea r exhaus t manifold s (A/ T
se e pag e 9-5 ).
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Rocker Arm s an d Shaft s
Remova l
1. Scre w a 5 m m bol t int o eac h rocke r shaf t oi l contro l
orifice , the n pul l ou t th e rocke r shaf t oi l contro l ori -
fices .
ROCKE R SHAF TOIL CONTRO LORIFICEClean.
5 m m BOL T
O-RIN GReplace .
O-RING
Replace .
2. Remov e th e VTE C solenoi d valve , the n remov e th e
sealin g bolts .
WASHE R
Replace .
SEALIN G BOL T
WASHE RReplace .
FILTER/O-RIN GReplace.
SEA IN G VTE C SOLENOI D VALV E
BOL T
3. Bundl e th e rocke r arm s wit h rubber bands t o kee p
the m togethe r a s sets .
4 . Scre w a 1 2 x 1.2 5 m m bol t int o eac h rocke r shaft .
Remov e th e rocke r arm s whil e slowl y pullin g th e
rocke r shaft s ou t o f th e cylinde r head s towar d th e
transmissio n end .
ROCKE R AR M
ASSEMBL Y RUBBE
R BAN D
12 m m BOL T
12 m m BOL T
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Rocker Arm s an d Shaft s
Disassembly/Reassembl y
CAUTION: Afte r installin g th e rocke r shaf t orifice , tr y t o tur n th e rocke r shaf t t o mak e sur e tha t th e orific e ha s bee n
inserte d in th e hol e o f th e rocke r shaf t correctly . I f th e orific e i s i n place , i t shoul d no t turn .
NOTE :
• Identif y part s a s the y ar e remove d t o ensur e reinstallatio n i n origina l locations .
• Inspec t rocke r shaft s an d rocke r arm s (se e page s 6-3 3 an d 6-34 ).
• Rocke r arm s mus t b e installe d i n th e sam e positio n i f reused .
• Adjus t th e rocke r arm s afte r torquin g th e cylinde r hea d bolts .
Prio r t o reinstalling , clea n al l th e part s i n solvent , dr y them , an d appl y lubrican t t o an y contac t surfaces .
EXHAUST ROCKE R AR M ASSEMBLIE S
WASHER S
Replace .
INTAKE ROCKE R
SHAF T
WASHER S EXHAUS T ROCKE R
Replace . SHAF T RUBBE
R BAN D
RUBBE R BAN D
CYLINDE R NUMBE R
CYLINDE R NUMBE R
RUBBER BAN D
RUBBE R BAN D
EXHAUS T ROCKE R AR M ASSEMBLIE S
INTAK
E ROCKE R
SHAF T
EXHAUS
T ROCKE R
SHAF T
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Rocker Arms and Lost Motion Assemblies

Inspection

NOTE: When reassembling the primary rocker arm, care-

fully apply air pressure to the oil passage of the rocker

arm.

PRIMARY ROCKER ARM

MID ROCKER ARM

SECONDARY

ROCKER ARM

PISTONS

1. Inspect the rocker arm pistons. Push them manually.

— If they do not move smoothly, replace the rocker

arm assembly.

PRIMARY

MID

SECONDARY

Check piston movement

NOTE:

• Apply oil to the pistons when reassembling.

• Bundle the rocker arms with rubber bands to

keep them together as sets.
2. Remove the lost motion assembly from the cylinder

head and inspect it. Pushing it gently with the finger

will cause it to sink slightly. Increasing the force on

it will cause it to sink deeper.

— If the lost motion assembly does not move

smoothly, replace it.

LOST MOTION ASSEMBLYProCarManuals.com