air conditioning ACURA NSX 1991 Service Repair Manual

General Info
Specifications
Maintenance
Engine
Cooling
Fuel and Emissions
’91’92 Models
’93’94 Models
’95’96 Models
*TransaxleSuspension
*Brakes (Including ABS)
*Body
*Heating, Ventilation and
Air Conditioning
*Body Electrical
*Engine Electrical
*SRS
1991-96 NSX Main Menu
As sections w/ * include SRS components,
special precautions are required when servicing.
Steering
’91’94 Models
’95’96 Models
ProCarManuals.com

15. Loosen the idler pulley center nut and adjusting nut,

then remove the air conditioning (A/C) compressor
belt.

IDLER PULLEY
CENTER NUT

45 N·m
(4.5 kg-m,

33 lb-ft)

ADJUSTING

NUT

A/C COMPRESSOR

BELT

16. Remove the crankshaft pulley (see page 6-12 ('91-'93)
or ('94-'96)

17. Remove the rubber seal from the adjusting bolt,
then remove the middle covers and lower cover.

6 x 1.0 mm

12 N·m
(1.2 kg-m.

9 Ib-ft)
LOWER COVER RUBBER SEAL
6 x 1.0 mm
12 N·m
(1.2 kg-m,

9 lb-ft)

9 x
1.25
mm

22 N·m
(2.2 kg-m,

16 Ib ft)
IDLER PULLEY
ASSEMBLYCOLLAR
MIDDLE COVER
18. Loosen the adjusting boll 180
0
turn. Push the ten-

sioner to remove tension from the timing belt, then
re tighten the adjusting bolt.

ADJUSTING BOLT
Do not remove. When
adjusting, loosen

it
180°.

19. Remove the timing belt from the pulleys.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

Recovery

Only use service equipment that is U.L.-listed and is cer-

tified to meet the requirements of SAE J2210 to remove

HFC-134a (R-134a) from the air conditioning system.

CAUTION: Exposure to air conditioner refrigerant

and lubricant vapor or mist can irritate eyes, nose

and throat. Avoid breathing the air conditioner

refrigerant and lubricant vapor or mist.

If accidental system discharge occurs, ventilate work

area before resuming service.

R-134a service equipment or vehicle air conditioning sys-

tem should not be pressure tested or leak tested with

compressed air.

Some mixtures of air and R-134a have

been shown to be combustible at elevated pressures

and can result in fire or explosion causing injury or

property damage. Never use compressed air to pres-

sure test R-134a service equipment or vehicle air

conditioning systems.

Additional health and safety information may be obtained

from the refrigerant and lubricant manufactures.

1. Connect a R-134a refrigerant Recovery/Recycl-

ing/Charging System to the car as shown following

the equipment manufacturer's instructions.

2. Measure the amount of refrigerant oil removed

from the A/C system after the recovery process is

completed.

NOTE: Be sure to install the same amount of new

refrigerant oil back into the A/C system before

charging.
Recovery/Recycling/Charging System.ProCarManuals.com

A/C System Service

Evacuation

Only use service equipment that is U.L.-listed and is cer-

tified to meet the requirements of SAE J2210 to remove

HFC-134a (R-134a) from the air conditioning system.

CAUTION: Exposure to air conditioner refrigerant

and lubricant vapor or mist can irritate eyes, nose

and throat. Avoid breathing the air conditioner

refrigerant and lubricant vapor or mist.

If accidental system discharge occurs, ventilate work

area before resuming service.

R-134a service equipment or vehicle air conditioning sys-

tem should not be pressure tested or leak tested with

compressed air.

Some mixtures of air and R-134a have

been shown to be combustible at elevated pressures

and can result in fire or explosion causing injury or

property damage. Never use compressed air to pres-

sure test R-134a service equipment or vehicle air

conditioning systems.

Additional health and safety information may be obtained

from the refrigerant and lubricant manufacturers.

1. When an A/C System has been opened to the at-

mosphere, such as during installation or repair, it

must be evacuated using a R-134a refrigerant

Recovery/Recycling/Charging System. (If the

system has been open for several days, the

receiver/dryer should be replaced).

2. Connect a R-134a refrigerant Recovery/Recycl-

ing/Charging System to the car as shown follow

the equipment manufacturer's instructions.

NOTE: If low pressure does not reach more than

700 mm Hg (27 in-Hg) in 1 5 minutes, there is pro-

bably a leak in the system. Partially charge the

system and check for leaks (see Leak Test).
Recovery/Recycling/Charging SystemProCarManuals.com

Warning/Caution Label Locations

SRS CAUTION LABELS: Refer to page 1-8.
FROZEN

BATTERY CAUTION

BATTERY

CAUTION

RADIATOR BLEED

PLUG CAUTION
AIR CONDITIONING
R-134a CAUTION (U.S.A only)
EXPANSION
TANK CAP

CAUTION

ENGINE COOLANT CAUTION PRECAUTION

SPARK PLUG

CAUTION

TIRE INFORMATION
ABS CAUTION

ABS and BRAKE

FLUID CAUTION

RETRACTABLE

HEADLIGHT CAUTION

EMISSION CONTROL

INFORMATION and

VACUUM HOSE

ROUTING DIAGRAM

(cont'd)ProCarManuals.com

Warning/Caution Label Locations

SRS CAUTION LABELS: Refer to page 1-8.
FROZEN

BATTERY CAUTION

BATTERY

CAUTION

RADIATOR BLEED

PLUG CAUTION
AIR CONDITIONING R-134a CAUTION(U.S.A only)

EXPANSION

TANK CAP CAUTION
ENGINE COOLANT
CAUTION • PRECAUTION
SPARK PLUG
CAUTION

TIRE INFORMATION
EMISSION CONTROL

INFORMATION and

VACUUM HOSE

ROUTING DIAGRAM
RETRACTABLE

HEADLIGHT CAUTION
ABS and BRAKE

FLUID CAUTION ABS CAUTION

(cont'd)ProCarManuals.com

Engine Removal/Installation
(cont'd )


32. Remove the rear beam rod assembly.
33. Remove the front beam. Lower and suspend the air conditioning (A/C) compressor. Reinstall the frontbeam.

NOTE:

PARKING BRAKE CABLE

Hang with

wire or rope.

FRONT BEAM

REAR BEAM

ROD ASSEMBLY

Remove.

A/C COMPRESSOR

Do not remove the compressor hoses.
Hang the A/C compressor with wire
or rope as shown.
Do not let it hang from hoses.
Retorque the two nuts
NOTE:

Do not remove the compressor hoses.
Do not let the compressor hang from hoses.
34. Remove the left and right parking brake cables.
35. Disconnect the stabilizer bar end links from the knuckles, remove the bar. Separate the dampers
from the knuckles.ProCarManuals.com

Cylinder Head/Valve Train
Illustrated Index

CAUTION: To avoid damaging the cylinder head, wait

until the engine coolant temperature drops below
100 °F (38 °C) before removing it.NOTE:

CAP NUT

6 x 1.0 mm
10 N .
m
(1.0 kg-m,

7 Ib-ft)
CYLINDER

HEAD COVER

WASHER AND

GROMMET

After installation, fill the engine with oil up to the

specified level, run the engine for more than 3

minutes, then check for oil leakage.

When installing the new crankshaft;

tighten the crankshaft pulley bolt to 280 N .
m (28

kg-m, 203 Ib-ft),

loosen bolt.


retighten it to

250 N .
m (25 kg-m, 181 Ib-ft).

CYLINDER HEAD

COVER
RUBBER SEALS
Replace when damaged

or deteriorated.

6 x 1.0 mm
12N .
m (1.2 kg-m,

9 Ib-ft)

TIMING BELT
REAR MIDDLE

COVER

TIMING BELT
FRONT MIDDLE

COVER
ADJUSTING BOLT

10 x
1.25
mm

43N .
m (4.3 kg-m,

31 Ib-ft)

For adjustment only,
do not remove.

ALTERNATOR

BELT

Adjustment,
section 23

6 x 1.0 mm
12N .
m
(12
kg-m.

9 Ib-ft)

CRANKSHAFT PULLEY
Remove any oil.

SPECIAL BOLT
16x 1.5 mm

250N .
m (25 kg-m,

181 Ib-ft

Tightening torque for
a new crankshaft.

203

Apply oil to
the bolt threads, but not
to the surface that contacts the washer.
6 x 1.0 mm

12N .
m (1.2 kg-m,

9 Ib-ft)
AIR CONDITIONING (A/C) BELT
Adjustment, section 22
6x 1.0 mm

12N .
m (1.2 kg-m, 9 Ib-ft)

(cont'd)

A/C ADJUSTING

PULLEY BRACKET

RUBBER SEAL
Install with concave

surface facing out.

Remove any oil.
TIMING BELT

DRIVE PULLEY

Remove any oil.

Install with concave
surface facing in.
Remove any oil.

TIMING BELT

Inspection, page 6-22
Adjustment, page 6-22 Replacement, page 6-23 to 26
RUBBER SEALS

Replace when damaged
or deteriorated.
CAP NUT

6 x 1.0 mm

10N .
m (1.0 kg-m,

7 Ib-ft)

TIMING BELT

LOWER COVER

RUBBER SEAL
KEY

Remove any oil.

TENSIONER

280

250N.m

25
kg-m,
181 Ib-ft)

(28
0
0
0

Use new O-rings and gaskets when reassembling.

Replace rubber seals, if damaged or deteriorated.

Prior to installing the cylinder head cover, apply a thin

layer of liquid gasket to the mating surface of the

cylinder head cover and rubber seals to prevent the
rubber seal from falling off.ProCarManuals.com

45N
.
m (4.5 kg-m. 33 Ib-ft)

14. Remove the connector, the terminal and the alternator.
1 5. Remove the bolt from the side engine mount, then
push the side mounting bracket into the housing of
the body (page 5-27).
16. Remove the transmission mount.
17. Remove the cylinder head covers.

18. Turn the crankshaft so that the No. 1 piston is at

top dead center (page 6-25, 26).

19.
Install
a
brace
under
the
engine, then
tilt
the
engine approximately 5° using a jack.
Timing Belt
Removal (cont'd)
BELT COVER
ALTERNATOR
20. Remove the alternator bracket stiffener.
ALTERNATOR BRACKET
STIFFENER

21. Remove the air conditioning (A/C) compressor ad-
justing pulley and belt.

22. Remove the dipstick pipe mounting bolt, then re- move the front and rear timing belt middle covers.
23. Remove the crankshaft pulley, then remove the tim- ing belt lower cover.
24. Loosen the timing belt adjusting bolt 180° and release the belt tension.
NOTE: Push the tensioner to release tension from
the belt, then retighten the adjusting bolt.
ADJUSTING BOLT
Do not remove. When

adjusting, loosen

it
180°.
25. Remove the timing belt from the pulleys.
CAUTION: Do not crimp or bend the timing belt more

than 90° or less than 25 mm (1 in.) in diameter.
DIAMETER

1.0 x
1.25
mm

45N .
m (4.5 kg-m,

33 Ib-ft)

6 x 1.0 mm

12N .
m (1.2 kg-m, 9 Ib-ft) DIPSTICK PIPE

8x1.25 mm

22N .
m

(2.2 kg-m,
16 Ib-ft)
9 Ib-ft)
6 x 1.0 mm

12N .
m (1.2 kg-m.

6 Ib-ft29

ADJUSTING BOLT

8x1.25 mm

8N .
m (0.8 kg-m,

1.0 x
1.25
mm
8x1.25 mm

12N .
m (1.2 kg-m,

9 Ib-ft)ProCarManuals.com