1991 ACURA NSX oil temperature

Cylinder Heads

Illustrated Index (cont'd)
CAUTION:
To
avoid
damage,
wait
until
the
engine
coolant
temperature
drops
below
100°F
(39-C]
before
removing
the
cylin-

der head.

NOTE: Use new O-rings and gaskets when reassembling.

Prior to reassembling, clean all the parts in solvent, dry them, and apply lubricant to any contact parts.

REAR VARIABLE VALVE TIMING
AND VALVE LIFT ELECTRONIC CONTROL
SYSTEM (VTEC) SOLENOID VALVE

Troubleshooting, page 6-3 ('91-'93) or ('94-'96)

EXHAUST GAS
RECIRCULATI0N (EGR) VALVE

6 x 1 .0 mm
12 N·m
(1.2 kg-m.
9 Ib-ft)
8 x
1.25
mm

22 N·m
(2.2 kg-m,
16 Ib-ft)
ENGINE COOLANT
TEMPERATURE (ECT) SENSOR
18 N·m (1.8 kg-m, 13 Ib-ft)

8 x
1.25
mm
22 N·m (2.2 kg-m. 16 lb-ft)
FRONT VTEC SOLENOID VALVE

Troubleshooting. page 6-3

SEALING BOLTS

60 N·m
(6.0 kg-m,

43 lb-ft)

OIL PRESSURE

GAUSE SENDING
UNIT (section 23)

ROCKER

SHAFTS
WASHERS
Replace.

8 x
1.25
mm

22 N·m
(2.2 kg-m,16 Ib-ft)
DOWEL PIN

0-RING

Replace.

ECT SWITCH

28 N·m
12.8 kg-m.

20 lb-ft

O-RING

Replace.

O-RING

Replace.

ROCKER ARM ASSEMBLY[PRIMARY. MID, SECONDARY]

Inspection, page 6-32 ('91-'93) or ('94-'96)

ROCKER SHAFT

OIL CONTROL
ORIFICE

Remove with 5 mm

boit and clean.

FILTER
Replace.

GASKET

Replace.

O-RING

Replace.ProCarManuals.com

Cylinder Heads

Removal

Engine removal is not required for this procedure. Make sure jacks and safety stands are
placed properly and hoist brackets ere attached to cor- rect positions on the engine.
CAUTION: Use a fender cover (special tool) to avoid damaging
painted surfaces. Unplug the wiring connectors carefully while holding
the connector portion to avoid damage.
To avoid damaging the cylinder heads, wait until the
engine coolant temperature drops below 100°F
(38°C) before loosening the retaining bolts. Do not open the engine cover when the roof panel is
stored (NSX-T open top).
NOTE:
Unspecified items are common.

Mark all wiring and hoses to avoid misconnection.
Also, be sure that they do not contact other wiring or

hoses or interfere with other parts.

Inspect the timing belt before removing the cylinder

head.

Turn the crankshaft pulley SO that the No. 1 piston is at top dead center (see page 6-19 ('91-'93) or ('94-'96)).
1. Disconnect the negative terminal from the battery.
2. Remove the expansion tank cap. Use care when removing the expan-
sion tank cap to avoid scalding by engine coolant
or steam.
3. Raise the car, then remove the right rear wheel/tire.
4. Drain the engine coolant (see page 10-5 ). 5. Remove the engine under guard, then remove the
front exhaust pipe A.

GASKETS
Replace.

FRONT EXHAUST

PIPE A

SELF-LOCKING NUT

10 x
1.25
mm

55 N·m (5.5 kg-m, 40 Ib-ft)
Replace.
SELF- LOCKING NUT

8 x
1.25
mm

22 N·m (2.2 kg-m. 16 Ib-ft)

Replace.

6. Remove the rear exhaust pipe A.

SELF- LOCKING NUT

8 x
1.25
mm
22 N·m (2.2 kg-m, 16 Ib-ft)

Replace.

REAR

EXHAUST

PIPE A

SELF-LOCKING NUT
10 x
1.25
mm

55 N·m (5.5 kg-m.

40 Ib-ft)

Replace.
GASKETS

Replace.

7. Remove the engine oil cooler base assembly (see
page 6-15 ('91-'93) or ('94-'96).

8. Lower the car.
9. Remove the strut brace (see page 5-3 ).ProCarManuals.com

24. Remove the engine wire harness connectors and
wire harness clamps from the cylinder head and
intake manifold, Six injector connectors
Intake air temperature (IAT) sensor connector
CKP/CYP sensor connector
Heated oxygen sensor (HO2S) connectors

Ignition control module (ICM) connectors

Engine coolant temperature (ECT) sensor connec-

tor

ECT gauge sending unit connector
ECT switch connector
Exhaust gas recirculation (EGR) valve lift sensor

connector

Throttle position sensor connector Engine oil pressure gauge sending unit connector
Knock sensor connector
VTEC solenoid valve connectors
VTEC pressure switch connectors
Engine oil pressure switch connector
Alternator connector

Alternator terminal

Throttle body 6P connector

25. Remove the ignition coils and connector.

26. Remove the EGR pipe and intake manifold assem- bly.

8 x 1.25mm

22 N·m (2.2 kg-m, 16 Ib-ft)

6 x 1.0 mm
12 N·m
(1.2 kg-m,

9 lb-ft)

GASKETS

Replace. INTAKE
MANIFOLD
ASSEMBLY

GASKET
Replace.
27. Loosen the adjusting nut and idler pulley center nut,
then remove the air conditioning compressor belt

(see page 6-17('91-'93) or ('94-'96)).

28. Remove the cover, adjusting bolt, mounting bolt and mounting nut, then remove the alternator belt
and alternator.

COVER

MOUNTING BOLT
10 x
1.25
mm

45 N·m (4.5 kg·m,

33 Ib-ft)

MOUNTING NUT
10 x
1.25
mm

45 N·m (4.5 kg·m.

33 Ib·ft)
ALTERNATOR

BELT

29. Disconnect the knock sensor connector, then remove
the wire holder.

6 x 1.0 mm
12N·m (1.2 kg-m, 9 Ib-ft)

KNOCK SENSOR
WIRE HOLDER
(cont'd)

6 x 1.0 mm

12 N·m (1.2 kg-m, 9 Ib-ft)

ADJUSTING

BOLTProCarManuals.com

6 x 1. 0 m m12 N- m (1. 2 kg-m ,9 Ib-ft )
OIL PUM P
Appl y liqui d
gaske t t o bloc kmatin g surfaces .
SPECIAL BOLT S6 x 1. 0 m m12 N- m (1. 2 kg-m ,9 Ib-ft )Replace .
SPECIAL BOLT S8 x 1.2 5 mm22 N- m (2. 2 kg-m ,16 Ib-ft )Replace .
NOTE:
• Use liqui d gasket , Par t No. 08718-0001 .
• Chec k tha t th e matin g surface s ar e clea n an d
dry befor e applyin g liqui d gasket .
• Appl y liqui d gaske t evenly , bein g carefu l t o cove r
al l o f th e matin g surface .
• T o preven t leakag e o f oil , appl y liqui d gaske t t o
th e inne r thread s of the bol t holes .
LEFTSIDE COVE R
Apply liqui d gaske talong th e broke n line .
OIL PUM PApply liqui d gaske talong th e broke n line .
• D o no t instal l th e part s i f fiv e minute s o r mor e
have elapse d sinc e applyin g liqui d gasket .
Instead reappl y liqui d gaske t afte r removin g ol d
residue .
• Afte r assembly , wai t a t leas t 2 0 minute s befor e
filling th e engin e wit h oil .
9. Instal l th e oi l pas s pip e an d joint .
10 . Instal l th e baffl e plate .
11 . Instal l th e oi l screen .
12 . Instal l th e oi l pa n (se e pag e 8-10 ).
CAUTION : Wheneve r an y crankshaf t o r connec -
tin g ro d bearin g i s replaced , afte r reassembly , ru n
th e engin e a t idlin g spee d unti l i t reache s norma l
operatin g temperature , the n continu e t o ru n fo r ap -
proximatel y 1 5 minutes .
OIL PUM P SIDE :
6 x 1. 0 m m12 N- m (1. 2 kg-m , 9 Ib-ft )
OIL SCREE NBAFFLE PLAT E
OIL PAS SPIPE
ProCarManuals.com

Ignition Coil Test

1. With the ignition switch OFF, remove the ignition

coil.

2. Using an ohmmeter, measure resistance between

the terminals. Replace the coil if the resistance is

not within specifications.

NOTE: Resistance will vary with the coil

temperature; specification is at 77°F (25°C).

Primary Winding Resistance

(Between the A and B terminals): 0.9—1.1 ohms

3. If primary winding resistance is OK, substitute a

known-good ignition coil, and check the system

operation.

If the system is normal, replace the original ignition

coil.
A TERMINAL

B TERMINAL
IGNITION

COIL

SECONDARY

WINDING

TERMINAL

SPARK PLUG

VOLTAGE

SENSOR

SECONDARY

WINDING

TERMINALProCarManuals.com

Gauge Assembly
Gauge/Terminal Location Index
SRS components are located in this area. Review the SRS component locations, precautions, and procedures in the SRS

section (24) before performing repairs or service.

SPEEDOMETER:

Indicates 60 mph [60km/h] at 1.026 [637]

rpm of the vehicle speed sensor (VSS).
FUEL GAUGE: Gauge test, page 23-134 Sending Unit Test, page 23-135

VOLTAGE METER:
If, with the No. 5 (15 A) fuse

and other gauges

OK, the pointer of the

voltage meter does not move at all,
replace the voltage

meter.

SAFETY INDICATOR SYSTEM:
See page 23-145 ('93-'96) ('91-'92)A/T GEAR POSITION
INDICATOR SYSTEM:
See page 23-156 ENGINE OIL PRESSURE
GAUGE:
Test page 23-137
ENGINE COOLANT TEMPERATURE (ECT) GAUGE:
Gauge Test, page 23-136 Sender Test, page 23-136
TACHOMETER:

Indicates 100 rpm at 300 pulses per minute

of the igniter unit.ProCarManuals.com

Disassembly

NOTE:
Handle the terminals and printed circuit boards carefully to avoid damaging them.
Replace
the
speedometer,
trip
meter,
and
printed
circuit
board
A as a
unit
if any of
them
is
faulty. Replace the tachometer, odometer, and printed circuit board B as a unit if any of them is faulty.

SPEEDOMETER MOUNTING SCREWS (x3) TACHOMETER MOUNTING SCREWS (x3)
VOLTAGE/FUEL GAUGE
MOUNTING SCREWS (x5) ENGINE COOLANT TEMP./ENGINE OIL PRESSURE
GAUGE MOUNTING SCREWS (x6)
HOUSING
ENGINE COOLANT

TEMPERATURE/

ENGINE OIL PRESSURE GAUGE

Test, page 23-136 and 137

SAFETY INDICATOR
MOUNTING SCREWS (x2) SHIFT INDICATOR
TACHOMETER

Specification, page 23-121
A/T GEAR POSITION
INDICATOR

See page 23-152 ('94-'96) ('91-'93)


LIGHT HOUSING
ODOMETER
SPEEDOMETER

Specification, page 23-121

TRIP METER FUEL/VOLTAGE GAUGE

Test, page 23-121

and 134

FACE PANEL PRINTED CIRCUIT
BOARD B
BOARD-TO-BOARD

CONNECTOR

PRINTED CIRCUIT
BOARD COVER
PRINTED CIRCUIT
BOARD A
SAFETY INDICATOR

See page 23-145 ('93-'96)('91-'92)

TRIP METER
RESET BUTTON
VISORProCarManuals.com

R-Replace I — Inspect After inspection, clean, adjust, repair or replace if necessary.

sec
and

PAGE
NO

19-6 19-8

19-18

19-26

19-4
19-10

19-69
19-41

19-43 19-44

19-62

18-7
17-21

('93-'96)
('94-'96)
17-60('94-'96)
('94-'96)


17-6

18-14

18-30

Under severe driving conditions, service these items more often.
Severe Driving Conditions
Items marked or in the chart indicate you will need some services more frequent-

ly in certain severe driving conditions.

The conditions are:
A: Driving loss than 5 miles (8 km) per trip, or, in freezing temperatures, driving less than 10 miles (16 km) per trip.
B: Driving, on rough or muddy roads, or de-iced roads.

C: Driving in extremely dusty conditions.
D: Extensive idling or driving long periods at slow speeds, such as a delivery vehicle. *6 : Ruler to Base Service Manual ('93 NSX, P/N 61SL002).
Services for Severe Driving Conditions
—
Clean
the air
cleaner
element
every
7,500 miles
(12,000
kml or 6
months
and
replace every
30,000
miles (48,000 km) or 24 months under condition B or C,

— Replace engine oil and oil filter every 3,750 miles (6,000 km) or\
3 months under conditions A, B, C, Dor E.
— Replace transmission oil every 15,000 miles (24,000 km) or 1 7. months under conditions D of E.

— Inspect front brake discs and calipers, and rear brake dises, calipers and pads every 7,500 miles (12,000

km) or 6 months under conditions B, C of D.
— Inspect the power steering system every 7,500 miles (12,000 km) or 6 months under conditions A, B or C.ProCarManuals.com