1991 ACURA NSX set clock

Valve Clearance

Adjustment

NOTE:
Valves should be adjusted cold, when the cylinderhead temperature is less than 100°F (38°C).
Adjustment is the same for both intake and exhaust valves.
Adjust valve clearance at TDC of each cylinder.
Do not rotate the engine counterclockwise. The tim-
ing belt could jump a tooth on the camshaft pulleys.

1. Remove the cylinder head covers.
NOTE: Refer to pages 6-47 ('91-'93),or ('94-'96), 6-48
('91-'93), or ('94-'96) when installing the cylinder head cover.

FRONT:

No.6 No.5 No.4
EXHAUST

INTAKE

No.6 No.5 No.4

REAR:
No.3 No.2 No.1

INTAKE

EXHAUST

No.3 No.2 No.1 (cont'd)

CRANKSHAFT PULLEY
TDC MARK (WHITE PAINT)
POINTER ON

THE LOWER

COVER

REAR:

Number 1 PISTON at TDC

FRONT:

2. Rotate the crankshaft to set No. 1 piston at TDC.
TDC mark (white paint) on the crankshaft pulley
should align with pointer on the timing lower
cover, and TDC grooves on the camshaft pulleysshould align with timing belt cover plates.ProCarManuals.com

Timing Belt

Installation

Install the timing belt in the reverse order of removal;

Only key points are described here.

NOTE: Clean the middle and lower covers before instal-

lation.

1. Set the timing belt drive pulley so that the No. 1 pis-

ton is at top dead center (TDC). Align the mark on

the teeth side of the timing belt drive pulley to the

pointer on the oil pump.

POINTER

MARK

KEY

TIMING BELT

DRIVE PULLEY

Clean.

2. Set the front camshaft pulleys so that the No. 1 pis-

ton is at TDC. Align the TDC marks on the front

exhaust camshaft pulley and front intake camshaft

pulley to the pointer on the back cover.

Pointer on the

back cover.

FRONT INTAKE

CAMSHAFT PULLEY
FRONT EXHAUST

CAMSHAFT PULLEY

TDC MARKS
3. Set the rear camshaft pulleys so that the No. 1 pis-

ton is at TDC. Align the TDC mark on the rear intake

camshaft pulley to the pointer on the back cover.

Align the rear exhaust camshaft pulley one half

tooth clockwise past TDC.

REAR EXHAUST

CAMSHAFT PULLEY
Pointer on the

back cover.
REAR INTAKE

CAMSHAFT PULLEY

TDC MARKS

4. Install the timing belt tightly in the sequence shown.

Timing belt drive pulley (crankshaft)

Adjusting pulley Front exhaust camshaft pulley

Front intake camshaft pulley Water pump

pulley Rear intake camshaft pulley Rear

exhaust camshaft pulley.

NOTE: Make sure the timing belt drive pulley and

camshaft pulleys are at TDC.

5. Tension the timing belt between the pulleys in the

sequence A to E as shown below.ProCarManuals.com

II. Engine Control Module (ECM) Reset Procedure

Either of the following actions, will reset the ECM.

• Using the OBD-II scan tool or Honda PGM Tester to clear the ECM's memory.

NOTE: See the OBD-II scan tool or Honda PGM Tester user's manuals for specific operating instructions.

• Turn the ignition switch OFF. Remove the CLOCK (7.5 A) fuse from the under-hood fuse/relay box for 10 seconds.

UNDER-HOOD

FUSE/RELAY BOX
CLOCK

(7.5 A) FUSE

III. Final Procedure (this procedure must be done after any troubleshooting)

1. Remove the SCS Service Connector if it is connected.

NOTE: If the SCS service connector is connected and there are no DTCs stored in the ECM, the MIL will stay on

when the ignition switch is turned on.

2. Do the ECM Reset Procedure.

3. Turn the ignition switch OFF.

4. Disconnect the OBD-II scan tool or Honda PGM Tester from the Data Link Connector,ProCarManuals.com

Preset Torqu e
Inspectio n
On-Car:
1 . Bloc k th e fron t wheels .
2 . Shif t t o low gear .
3 . Lif t u p rea r wheels , an d plac e th e safet y stan d (Lif t
an d Suppor t Points , se e sectio n 1 ).
4 . Measur e prese t torqu e clockwis e usin g a torqu e
wrenc h a s shown .
Standard: 120-280 N-m (12-28 kg-m,
87-20 3 Ib-ft )
Servic e Limit : 6 0 N- m (6 kg-m , 4 3 Ib-ft )
TORQU E WRENC H
RIGH T REA R WHEE L
SAFETY STAN D
5. I f prese t torqu e is les s tha n th e servic e limit , replac e
th e limite d sli p differentia l clutc h set .
NOTE : Adjus t th e 6 5 m m (differentia l housin g cove r
side ) an d 11 2 m m (differentia l housin g cove r side )
shim s wheneve r th e clutc h se t i s replaced . Assembly
:
Plac e on e specia l too l i n a vise . Plac e th e lef t sid e
o f th e differentia l assembl y o n th e specia l tool , the n
prese t th e differentia l wit h 3- 5 rotations , counter -
clockwise .
DIFFERENTIA L
INSPECTIO N TOOL S
07MAJ-PR90100
2. Measur e prese t torqu e counterclockwis e usin g a tor -
qu e wrenc h a s shown.
Standard :
60-140 N- m (6-1 4 kg-m ,
43-10 1 Ib-ft )
Servic e Limit : 3 0 N- m (3 kg-m , 2 2 Ib-ft )
TORQU E WRENC H
DIFFERENTIA L
INSPECTIO N TOOL S
07MAJ-PR90100
3 . I f prese t torqu e is les s tha n th e servic e limit , replac e
th e limite d sli p differentia l clutc h set .
NOTE : Adjus t th e 6 5 m m an d 11 2 m m shim s
wheneve r th e clutc h se t i s replaced .
ProCarManuals.com

Preset Torque

Inspection
On-Car:

1. Lift up right rear wheel,
and place the safety stand.

(Lift and Support Points, see section 1).
2. Block the other three wheels.
3. Measure preset torque clockwise using a torque wrench as shown.

Standard:
60–140 N·m

(6–14 kg-m, 43–101 Ib-ft)

Service Limits: 30 N·m (3 kg-m, 22 Ib-ft)

TORQUE WRENCH
RIGHT REAR WHEEL SAFETY STAND

4. If preset torque is less than the service limit, replace the clutch discs with new ones.
NOTE: Adjust the thrust shim whenever the clutch
discs are replaced (see page 15-22).
Assembly:

1. Place one special tool in a vise. Place the left side of the differential assembly on the special tool, then
preset the differential with 3 – 5 rotations, both
clockwise and counterclockwise.

DIFFERENTIAL
INSPECTION TOOLS

07MAJ– PR90100

2. Measure preset torque clockwise using a torque wrench as shown.

Standard: 60–140 N·m
(6–14 kg-m, 43–101 Ib-ft)

Service Limit: 30 N·m (3 kg-m, 22 Ib-ft)

TORQUE WRENCH
DIFFERENTIAL
INSPECTION TOOLS

07MAJ – PR90100

3. If preset torque is less than the service limit, replace the clutch discs with new ones.
NOTE: Adjust the thrust shim whenever the clutch

discs are replaced (see page 15-22).
ProCarManuals.com

Troubleshooting Precautions

EPS Indicator Light

Under normal conditions, the EPS indicator light in the gauge assembly comes on when the ignition switch is turned to

the ON (II) position, then goes off after the engine is started. This indicates that the bulb and its circuits are operating cor-

rectly. If there is any trouble in the system, the EPS indicator light turns on during driving, and the power steering assist is

turned off. When the EPS indicator light comes on, the control unit memorizes the DTC. In this case, the control unit does

not activate the EPS system after the engine starts again but it keeps the EPS indicator light on.

Diagnostic Trouble Code (DTC)

• The lowest DTC is indicated first.

• The DTCs continue blinking until the ignition switch is turned off.

• The DTCs are erased from the control unit when the EPS control unit VBU power supply or connector is disconnected.

• The EPS system can be reset and the control unit's memory can be erased by disconnecting the CLOCK (7.5 A) fuse for

more than ten seconds.

Self-diagnosis:

The CPU (central processing unit) controls the following when it detects a problem during self-diagnosis:

1. Turns the EPS indicator light ON to alert the driver.

2. Power assist stops, and normal manual steering operation resumes (except DTC 21 and DTC 33).

3. The EPS control unit memorizes the diagnostic trouble code (DTC).

4. After the DTC is stored in the control unit, the CPU stops self-diagnosis.

Troubleshooting:

• Before starting the troubleshooting, clear the DTC by disconnecting the CLOCK (7.5 A) fuse for ten seconds or more,

and test-drive the car. Check that the symptom of the trouble appears again, and then troubleshoot. If the problem is an

intermittent problem, the system does not become active after the engine starts even though the problem is solved.

• When both EPS indicator light and A/T "D" indicator light come on, perform the A/T troubleshooting first.

• When the customer's reported problem cannot be verified in the car, ask the customer about the conditions when the

EPS indicator light came ON, then test-drive the car under those conditions, if possible. If the EPS indicator light does

not come ON during the test, check for loose connections or poor contacts at the connectors by wiggling the harness,

etc.

• The connector terminal numbers are viewed from the wire side for the female terminals and from the terminal side for

the male terminals.

• After the repair, test-drive the car and check that the EPS indicator light does not come ON again during the test. (Refer

to the Symptom-to-System Chart for diagnostic period.)ProCarManuals.com

Installation

NOTE: Before installing the steering wheel, make sure

the front wheels are straight ahead.

CAUTION:

• Be sure to install the harness wires so that they are

not pinched or interfering with other car parts.

• Do not replace the original steering wheel with any

other design, since it will make it impossible to prop-

erly install the airbag. (Use only genuine Honda

replacement parts.)

• After reassembly, confirm that the wheels are still

straight ahead and that steering wheel spoke angle

is correct. If minor spoke angle adjustment is neces-

sary, adjust the tie-rods only. Do not remove and

reposition the steering wheel.

Confirm that the airbag assembly is securely

attached to the steering wheel; otherwise, severe per-

sonal injury could result during later airbag deploy-

ment.

1. Before installing the steering wheel, center the

cable reel.

Do this by first rotating the cable reel clockwise

until it stops.

Then rotate it counterclockwise (approximately two

turns) until:

— The yellow gear tooth lines up with the mark on

the cover.

— The arrow on the cable reel label points straight

up.

ARROW MARK

CABLE REEL

YELLOW GEAR TOOTH

ALIGNMENT MARK
2. Install the steering wheel.

NOTE: Be sure the steering wheel shaft engages

the cable reel.

STEERING WHEEL

NUT

Replace.

50 N-m

(5.0 kg-m, 36 Ib-ft)

PIN

3. Insert the cruise control set/resume 4P connector

and airbag 3P connector to the steering wheel clips.

4. Connect the horn connector.

CRUISE CONTROL

SET/RESUME SWITCHES

4P CONNECTOR

HORN

CONNECTOR

CABLE REEL

CONNECTOR
PINProCarManuals.com

Steering Wheel

Installation

5. Install the airbag assembly with new Torx bolts.

TORX BOLT

10 N-m (1.0 kg-m, 7 Ib-ft)

Replace.

TORX BOLTS

10 N-m (1.0 kg-m, 7 Ib-ft)

Replace.
AIRBAG ASSEMBLY

6. Disconnect the short connector from the airbag 3P

connector.

7. Connect the airbag 3P connector and cable reel 3P

connector.

8. Attach the short connector to the access panel, then

install the access panel on the steering wheel lower

cover.

ACCESS PANEL

SHORT CONNECTOR

(RED)
9. Connect the battery positive terminal, and then con-

nect the negative terminal.

10. After installing the airbag assembly, confirm proper

system operation:

• Turn the ignition to II: the instrument panel SRS

indicator light should come on for about six sec-

onds and then go off.

• Confirm operation of horn buttons.

• Confirm operation of cruise control set/resume

switch.

• Turn the steering wheel counterclockwise and

make sure the yellow gear tooth still lines up

with the alignment mark.

YELLOW GEAR TOOTH

ALIGNMENT MARKProCarManuals.com