1991 ACURA NSX oil filter

9. Relieve fuel pressure by loosening the service bolt
on the fuel filter about one turn (see section 11).
Do not smoke while working on the
fuel
system.
Keep open flame away from work
area. Drain fuel only into an approved container.
10. Remove the fuel feed pipe and fuel return hose.
11. Remove the wire harness cover, then remove the fuel pipe clamp.

22 N·m
(2.2 kg-m,
16 Ib-ft)

WIRE HARNESS

COVER
6 x 1.0 mm

12 N·m
(1.2 kg-m,

9 lb-ft)

FUEL FEED
PIPE

WASHERS
Replace.

FUEL RETURN

HOSE

12. Remove the brake booster vacuum hose and evapo- rative emission (EVAP) control canister hose.

BRAKE BOOSTER

VACUUM HOSE

EVAP CONTROL

CANISTER HOSE
13. Remove the expansion tank cap.

14. Raise the hoist to full height.
15. Drain the engine coolant (see page
10-5).
Loosen the drain plug from the radiator lower
tank. Remove two drain bolls from the water pipes.
Reinstall the drain bolts with new washers.
Loosen the front and rear engine drain bolts to
drain engine coolant from the cylinder heads.
Connect rubber hoses to the drain bolts.
16. Drain the transmission oil/fluid. Reinstall the drain plug with a new washer.
17. Drain the engine oil. Reinstall the drain plug with a
new washer.

18. Lower the hoist, then remove the air cleaner hous-

ing (see page 6-25 ('91-'93 Mode ls),or('95-'96 Models).

19. Disconnect two hoses, then remove the expansion

tank.

6 x 1.0 mm

10 N·m
11.0 kg-m,

7 lb-ft)

EXPANSION

TANK

WATER BYPASS

HOSES
(cont'd)ProCarManuals.com

VTEC
VTEC Solenoi d Valv e Inspectio n
1. Disconnec t th e 2 P connecto r fro m th e VTE C sole -
noi d valve .
2 . Measur e resistanc e betwee n th e BLU/YE L (front/rear )
terminal s an d bod y ground .
Resistance : appro x 1 4 - 3 0 ohm s
BLU/YE L
3. I f th e resistanc e i s withi n specifications , remov e th e
VTE C solenoi d valv e fro m th e cylinde r head , an d
chec k th e VTE C solenoi d valv e filte r fo r clogging .
• I f ther e i s clogging , replac e th e engin e oi l filte r
an d engin e oil .
VTE C SOLENOI D VALV E
VTE C SOLENOI D VALV E
FILTER/O-RIN G
Replace.
6 x 1. 0 m m12 N- m (1. 2 kg-m , 9 Ib-ft )
4. I f th e filte r i s no t clogged , pus h th e VTE C solenoi d
valv e wit h you r finge r an d chec k it s movement .
• I f VTE C solenoi d valv e is normal , chec k th e engin e
oi l pressure .
6 x 1. 0 m m12 N- m (1. 2 kg-m , 9 Ib-ft )
ProCarManuals.com

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

Oil Filte r
Replacemen t
CAUTION: Loose n th e oi l filte r carefull y whil e th e
engin e is hot , th e ho t oi l ma y caus e scalding .
1 . Remov e th e oi l filte r wit h th e specia l too l a s shown .
2 . Inspec t th e thread s an d rubbe r sea l o n th e ne w filter .
Wip e of f th e sea t o n oi l filte r base , the n appl y a ligh t
coa t o f oi l t o th e rubbe r sea l an d instal l th e filter .
3 . Afte r th e rubbe r sea l i s seate d agains t th e base ,
tighte n th e oi l filte r b y turnin g i t approximatel y on e
turn .
Torque : On e tur n (2 2 N- m (2. 2 kg-m , 1 6 lb-ft)) .
OIL FILTE R WRENC H
0791 2-611000 1
Torque : On e tur n
(2 2 N- m (2. 2 kg-m , 1 6 lb-ft) )
4. Star t th e engine , an d chec k th e filte r fo r oi l leakage .
ProCarManuals.com

Oil Pump
Removal/lnspection/lnstallation
1. Drain the engine oil. 2. Remove the timing belt (see page 6-15('91-'93)or('94-'96)).
3. Remove the dipstick and the pipe.
4. Remove the oil filter assembly.
5. Remove the oil pan.
6. Remove the oil screen.
7. Remove the baffle plate,
8. Remove the oil pass
pipe and the joint.
9. Remove the mounting bolts and the oil pump

assembly.

Replace.
O-RINGS
Replace.

OIL SCREEN OIL PASS PIPE

AND JOINT
BAFFLE PLATE

OIL PUMP
10. Remove the nine screws from the pump housing,

then separate the housing and cover.

11. Check the inner-to-outer rotor radial clearance.

Inner-to-Outer Rotor Radial Clearance
Standard (New): 0.05 – 0.21 mm (0.002 – 0.008 in)
Service Limit: 0.23 mm (0.009 in)

OUTER ROTOR

INNER ROTOR

12. Check the housing-to-rotor axial clearance. Housing-to-Rotor Axial Clearance
Standard (New): 0.02 – 0.07 mm
(0.001 – 0.003 in)

Service Limit: 0.12 mm (0.005 in)

PUMP HOUSING

OUTER ROTORProCarManuals.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

Engine Oil

Replacement

CAUTION: Remove the drain plug carefully while the en-

gine is hot, the hot oil may cause scalding.

1. Warm up the engine.

2. Drain the engine oil.

WASHER

Replace.

DRAIN PLUG

45 IM-m (4.5 kg-m, 33 Ib-ft)

3. Reinstall the drain plug with a new washer, and refill

with the recommended oil.

CAUTION: Do not overtighten the drain plug.

Requirement
API Service Grade: Use "Energy

Conserving II" SG or SH grade oil.

SAE
10W-30
preferred.

You can also an oil a cantainer that

bears API CERTIFICATION mark.

Capacity
5.0
(5.3
US qt, 4.4 Imp qt)

at change, including filter.

6.3
(6.7
US qt, 5.5 Imp qt)

after engine overhaul.

Change
Every 7,500 miles (12,000 km) or

6 months whichever comes first.
API CERTIFICATION MARK

The numbers in the middle of the API Service label tell

you the oil's SAE viscosity or weight. Select the oil for

your car according to this chart:

Ambient Temperature

An oil with a viscosity of 10W —30 is preferred for im-

proved fuel economy and year-round protection in the

car.

You may use a 5W —30 oil if the climate in your area is

limited to the temperature range shown on the chart.

4. Fill the engine with oil up to the specified level, run

the engine for more than 3 minutes, then check for

oil leakage and oil level.ProCarManuals.com

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

NOTE
SEC

and

PAGE

Service at the interval listed x 1,000 miles (or km) or after that number of months, whichever comes first.

19-6

19-8

19-18
Under severe driving conditions, service these items more often.
Severe Driving Conditions Items with an or in the chart will need service more often, if you drive in some
severe conditions.

The conditions are:

A: Repeated short distance driving.
B: Dusty conditions.

C: Severe cold weather. D: Areas with road salt or other corrosive materials.
E: Rough or muddy roads. 18-14
18-30
17-6
17-21

17-68
18-7
19-62

19-41
19-43
19-44 19-10
19-69 19-4
19-26

The services are:
Clean the air cleaner element every 7,500 miles (12,000 km) or 6 months and replace every 30,000 miles(48,000 km) or 24 months under condition B or E.
Replace engine oil and oil filter every 3,750 miles (6,000 km) or 3 months under condition A or B.
Inspect front brake discs and calipers, and rear brake discs, calipers and pads every 7,500 miles (12,000
km) or 6 months under condition A, B, D or E.
Inspect the power steering system every 7,500 miles (12,000 km) or 6 months under condition B, C or E.ProCarManuals.com