sensor ACURA NSX 1991 Service Repair Manual

Air Intake System
Throttle Body

Description

The throttle body is of the single-barrel side-draft type.

The lower portion of the throttle valve is heated by
engine coolant which is fed from the cylinder head. Theidle adjusting screw which increases/decreases bypass
air and the canister/purge port are located on the top of
the throttle body. A dashpot is used to slow the throttle as it approaches the closed position.
Inspection

CAUTION: Do not adjust the throttle stop screw since

it preset at the factory.
1. Start the engine and allow it to reach normal operating temperature (cooling fan comes on).
2. Disconnect the vacuum hose (to the canister) from the top of the throttle body; connect a vacuum
gauge to the throttle body.

DASHPOT

DIAPHRAGM
THROTTLE

STOP SCREW

IDLE ADJUSTING

SCREW

THROTTLE
ANGLE SENSOR

VACUUM PUMP/GAUGE

A973X-041 -XXXXX
THROTTLE

VALVE

THROTTLE

ACTUATOR
3. Allow the engine to idle and check that the gauge
indicates no vacuum. If there is vacuum, check the throttle cable
(page 11-113).
4. Check that vacuum is indicated on the gauge when
the throttle is opened slightly from idle.
If the gauge indicates no vacuum, check the
throttle body port. If the throttle body port is clogged, clean it with carburetor cleaner.
5. Stop the engine and check that the throttle cable operates smoothly without binding or sticking. If there are any abnormalities in the above steps,
check for:
Excessive wear or play in the throttle valve
shaft.
Sticky or binding throttle lever at full close

position.
Clearance between throttle stop screw and
throttle lever at full close position.ProCarManuals.com

Transmission Assembly

Removal
Make sure lifts are placed properly, and

hoist brackets are attached to correct position, (see

page 1-6).

CAUTION: Use fender covers to avoid damaging

painted surfaces.

1. Check and record the rear camber.
(see section 18).
2. Disconnect the battery negative (-), and positive (+) cables from the battery.
3. Drain transmission oil. Reinstall the drain plug with a new washer.

Corrosion resistant bolt/nut
TRANSMISSION
HOUSING BOLT

BACK-UP

LIGHT SWITCH

CONNECTOR

HARNESS HOLDER

STARTER MOTOR

CABLES

NEUTRAL SWITCH
CONNECTOR

STARTER
MOTOR
MOUNTING

BOLTS

TRANSMISSION

MOUNT

GROUND

CABLE

TRANSMISSION

HANGER
TRANSMISSION

MOUNTING BOLTS
JUMPER

CONNECTOR

CONTROL BOX

SPEED SENSOR

CONNECTOR
4. Remove the strut bar.

5. Remove the air cleaner case.

6. Remove the connectors from the control box and remove the control box.
CAUTION: Do not remove the vacuum tubes from
the control box.
7. Remove the wire harness holder, jumper connector and transmission ground cable.
8. Disconnect the switch connectors, then remove the back-up light switch and neutral switch.
9. Disconnect the starter motor cables, then remove the starter motor.
10. Remove the transmission housing bolts.ProCarManuals.com

11. Remove the parking brake cable holders from the rear beam rod.
12. Remove the rear beam rod.
13. Remove the front exhaust pipe A.

Corrosion resistant bolt/nut
SELF-LOCKING NUT
Replace.

GASKET

Replace.
SELF LOCKING NUT

Replace.

14. Remove the parking brake cable holder and the Anti-lock Brake sensor wire clamp.
1 5. Loosen the ball joint nut, then separate the toe control arm from the knuckle using the special tool (see section 18).
16. Remove the damper fork bolt.
17. Remove the ball joint nut using the special tool and separate the lower control arm from the knuckle (see section 18).
18. Remove the right driveshaft from the intermediate shaft.
Corrosion resistant bolt/nut
SELF-LOCKING NUT

Replace.
DAMPER FORK BOLT

PARKING

BRAKE

CABLE
DRIVESHAFT ANTI-LOCK

BRAKE

SENSOR

WIRE/CLAMP
LOWER

CONTROL
ARM
CASTLE NUTTOE CONTROL ARM

(cont'd)

CASTLE

NUTProCarManuals.com

Transmission Assembly

Removal (cont'd)

19. Remove the intermediate shaft heat cover and the intermediate shaft mounting bolts.
20. Pry the intermediate shaft out of the differential. Pull and remove it.
NOTE:

Coat all precision finished surfaces with clean engine oil or grease. Tie plastic bags over the driveshaft ends.

INTERMEDIATE SHAFT

SUPPORT BASE

SET RING
Replace.

INTERMEDIATE SHAFT

21. Remove the parking brake cable holder and the Anti-lock Brake sensor wire clamp.
22. Scribe a reference mark on the flange of the adjusting bolt, adjusting cam and lower control arm.
23. Loosen the ball joint nut, then separate the toe control arm from the knuckle using the special tool (see section 18).
24. Remove the damper fork bolt.
25. Remove the bolts and lower control arm from the side beam.
26. Remove the left driveshaft from the differential.
27. Pry the driveshaft out of the differential. Pull and remove it.
NOTE:
Coat all precision finished surfaces with clean engine oil or grease.
Tie plastic bags over the driveshaft ends.

INTERMEDIATE SHAFT

MOUNTING BOLT

INTERMEDIATE SHAFT

HEAT COVER

DAMPER FORK BOLT
TOE CONTROL ARM

LOWER CONTROL ARM
ADJUSTING

BOLT
ADJUSTING

CAM


SET RING

Replace.
ProCarManuals.com

CLUTCH RELEASE HANGER
RELEASE HANGER SPRING
RELEASE BEARING GUIDE
40 x 68 x 12.5 mm OIL SEAL
Replace.
10 x 20 mm DOWL PIN

CLUTCH HOUSING

SPEED SENSOR
SENSOR DUMMY COVER O-RING

Replace.

HOLDER PLATE
REVERSE SHIFT FORK ASSEMBLY Disassembly/Reassembly, page
13-16

REVERSE IDLE GEAR SHAFT

ASSEMBLY Disassembly/Reassembly, page
13-15
OIL GUIDE RING

90 mm WASHER
BEARING OUTER RACE
DIFFERENTIAL ASSEMBLY See section 15
OIL GUIDE PLATE
44 x 72 x 23 mm NEEDLE BEARING
BEARING RETAINING PLATE
COUNTERSHAFT ASSEMBLY Index, page
13-29

MAINSHAFT ASSEMBLY

Index, page

13-23
75 mm SPRING WASHER
32 x 46 x 7 mm OIL SEAL

Replace.
TRANSMISSION MAGNET

SHIFT FORK ASSEMBLY Disassembly/Reassembly, page
13-22

OIL PUMP ASSEMBLY
Disassembly/Reassembly, page
13-37

CHANGE HOLDER ASSEMBLY
Disassembly/Reassembly, page
13-19

UPPER COVER
SELECT LEVER ASSEMBLY
Removel, page
13-17 Installation, page 13-43
REVERSE SHIFT ARM
14x20 mm DOWEL PHIS

14 x 20 mm DOWEL PIN

Clean all parts thoroughly in solvent and dry with compressed air.

Illustrated Index

Lubricate all parts with oil before reassembly.

NOTE:
This transmission uses no gaskets between the major housings; use P/N 08718 — 0001 sealant.
Assemble the housings within 20 minutes after applying the sealant and allow it to cure at least 30 minutes after

assembly before filling the transmission with oil.
Always clean the magnet whenever the transmission housing is disassembled.
ProCarManuals.com

Transmission Housing
Removal

NOTE: Place the clutch housing on two pieces of wood

thick enough to keep the mainshaft from hitting the
workbench.

1. Remove the back-up light switch, neutral switch
and speed sensor.

SPEED SENSOR
NEUTRAL

SWITCH

BACK-UP LIGHT SWITCH
2. Remove the sealing bolts, springs and steel balls.
3. Remove the upper cover, then remove the transmission housing attaching bolts.
4. Remove the 36 mm sealing bolt.

ATTACHING

BOLTS
36 mm SEALING BOLT

SEARING
BOLT

SPRING

STEEL BALL

UPPER COVER
OIL GUIDE

PLATE

THRUST SHIM

6. Separate the clutch housing from the transmission

housing.

7. Remove the thrust shim and oil guide plate from the
transmission housing.
SNAP RING
SNAP RING PLIER

5. Expand the snap ring on the countershaft ball bear-

ing and remove it from the groove using a pair of

snap ring pliers.ProCarManuals.com

1 5. Tighten the transmission housing attaching bolts in

the numbered sequence shown below.

Torque: 45 N·m (4.5 kg-m, 33 Ib-ft)

16. Install the 36 mm sealing bolt.

NOTE: Apply Honda Genuine liquid gasket (P/N

08718-0001) to the flange.

17. Install the steel balls, spring and sealing bolts.

NOTE: Apply Honda Genuine liquid gasket (P/N

08718 — 0001) to the threads, but don't plug the

hole with liquid gasket.

18. Install the upper cover.

STEEL BALL

(3/8 in)

10 x
1.25

mm BOLTS

45 N·m

(4.5 kg-m,

33 Ib-ft)
14 x 1.0 mm SEALING BOLT

33 N·m (3.3 kg-m, 24 Ib-ft)

SPRING (L. 25 mm)

36 mm SEALING BOLT

35 N·m (3.5 kg-m, 25 Ib-ft)

STEEL BALL (5/16 in)

SPRING

(L. 30 mm)

SPRING

(L.
24.2
mm)

UPPER COVER
19. Install the back-up light switch and neutral switch.

NOTE: Apply Honda Genuine liquid gasket (P/N

08718 — 0001) to the threads.

20. Install the speed sensor.

6 x 1.0 mm BOLT

12 N·m (1.2 kg-m, 8.7 Ib-ft)

SPEED SENSOR

8 x 1.25 mm BOLT

26 N·m
(2.6
kg-m,

19 Ib-ft)
NEUTRAL SWITCH

25 N·m
(2.5
kg-m,

18 Ib-ft)

SPRING

(L. 30

mm)
16 x 1.0 mm

SEALING

BOLTS

42 N·m

(4.2 kg-m,

30 Ib-ft)

6 x 1.0 mm BOLTS

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

24 N·m (2.4 kg-m, 17 Ib-ft)

8 x 1.25 mm BOLTS

24 N·m (2.4 kg-m, 17 Ib-ft)
BACK-UP LIGHT SWITCH

25 N·m (2.5 kg-m, 18 Ib-ft)ProCarManuals.com

12. Install a new set ring on the end of the left driveshaft and intermediate shaft.
13. Install the left driveshaft.
14. Install the lower arm to the side beam.

CAUTION: Align the reference marks on the adjusting bolt, adjusting cam and lower control arm.
15. Install the damper fork bolt.

16. Install the ball joint nut to the toe control arm at the knuckle.

CAUTION: Make sure that the arrow marks on the toe control arm are aligned.

17. Install the ALB sensor wire clamp and parking brake cable holder.

Corrosion resistant bolt/nut

SELF-LOCKING NUT

Replace.
12 x
1.25
mm

95 N·m (9.5 kg-m, 69 Ib-ft)
SELF-LOCKING NUT

Replace.
12 x
1.25
mm

85 N·m (8.5 kg-m, 62 Ib-ft)

6 x 1.0 mm
10 N·m

(1.0 kg-m. 7 Ib-ft)

SELF-LOCKING NUT
14 x 1.5 mm

125 N·m

(12.5 kg-m, 90 Ib-ft)
8 x
1.25
mm

22 N·m (2.2 kg-m, 16 Ib-ft)

12 x
1.25
mm

95 N·m

(9.5 kg-m, 69 Ib-ft)

ADJUSTING

BOLT
ADJUSTING

CAM
SET RING

SELF-LOCKING NUT
Replace.
12 x
1.25
mm

95 N·m (9.5 kg-m, 69 Ib-ft)

18. Install the intermediate shaft and tighten the intermediate shaft mounting bolts to the intermediate shaft support
base.

19. Install the intermediate shaft heat cover.

SET RING
6 x 1.0 mm

10 N·m (1.0 kg-m, 7 Ib-ft)

8 x
1.25
mm

22 N·m

(2.2 kg-m, 16 Ib-ft)
(cont'd)ProCarManuals.com

20. Install the right driveshaft onto the intermediate shaft.

21. Install the castle nut on the lower control arm at the knuckle.

22. Install the damper fork bolt.23. Install the castle nut on the toe control arm at the knuckle.
CAUTION: Make sure that the arrow marks on the toe control arm are aligned.
24. Install the Anti-lock brake sensor wire clamp and parking brake cable holder.

Transmission Assembly

Installation (cont'd)

Corrosion resistant bolt/nut
6 x 1.0 mm
10 N·m

(1.0 kg-m, 7 Ib-ft)

8 x
1.25
mm

22 N·m (2.2 kg-m, 16 Ib-ft)
SELF-LOCKING NUT
Replace.
12 x
1.25
mm

85 N·m (8.5 kg-m, 62 Ib-ft) COTTER PIN
Replace. CASTLE NUT

12 x
1.25
mm

60 N·m
(6.0 kg-m, 43 Ib-ft) CASTLE NUT

10 x
1.25
mm

44 N·m

(4.4 kg-m, 32 Ib-ft)
COTTER PIN
Replace. DAMPER FORK BOLT
SELF-LOCKING NUT

Replace.

12 x
1.25
mm

95 N·m (9.5 kg-m, 69 Ib-ft)

25. Install the front exhaust pipe A.
26. Install the rear beam rod.
27. Install the parking brake cable.

SELF-LOCKING NUT
Replace.
10 x
1.25
mm

34 N·m (3.4 kg-m, 25 Ib-ft)
Corrosion resistant bolt/nut

GASKET,
Replace.

10 x
1.25
mm

60 N·m
(6.0 kg-m,

43 Ib-ft)

8 x
1.25
mm

22 N·m
(2.2 kg-m,
16 Ib-ft) SELF LOCKING NUT
Replace.
10 x
1.25
mm

55 N·m (5.5 kg-m, 40-lb-ft)
10 x
1.25
mm

60 N·m (6.0 kg-m, 43 Ib-ft)
12 x
1.25
mm

95 N·m (9.5 kg-m, 69 Ib-ft)
8 x
1.25
mm

22 N·m (2.2 kg-m, 16 Ib-ft)ProCarManuals.com

28. Install the transmission mount and 2 transmission
housing mounting bolts.
29. Install the starter motor and connect the starter motor cables.
30. Install the transmission ground cable and jumper connector, and connect the back-up light switch,
neutral switch and speed sensor connectors.
31. Install the control box and connect the control box
connectors.

Corrosion resistant bolt/nut
TRANSMISSION HOUSING
MOUNTING BOLTS
12 x
1.25
.mm

65 N·m (6.5 kg-m, 46 Ib-ft)

12 x
1.25
mm

75 N·m (7.5 kg-m, 54 Ib-ft)
12 x
1.25
mm

75 N·m (7.5 kg-m, 54 Ib-ft)
TRANSMISSION MOUNTING

BOLTS

10 x
1.25
mm

60 N·m (6.0 kg-m, 43 Ib-ft)
TRANSMISSION MOUNTING

BOLT

12 x
1.25
mm

95 N·m (9.5 kg-m, 69 Ib-ft)

CONTROL BOX

32. Install the air cleaner case.

33. Install the strut bar.

34. Refill the transmission with oil.
35. Connect the battery positive (+) and negative (-) cables to the battery.
36. Inspect the rear camber (see section 18).
37. Check the clutch operation.
38. Shift the transmission and check for smooth
operation.ProCarManuals.com