ACURA NSX 1991 Service Repair Manual

Road Test

NOTE:
Warm up the engine to normal operating temperature (the cooling fan comes on).
When the engine coolant temperature is below normal operating temperature, the shift point is higher than specifiedvehicle speed.
Range 1. Apply parking brake and block the wheels. Start the engine, then move the selector to while depressing the brake
pedal. Depress the accelerator pedal, and release it suddenly. Engine should not stall.
2. Check that shift points occur at approximate speeds shown. Also check for abnormal noise and clutch slippage.
NOTE: Throttle position sensor voltage represents the throttle opening.

DIGITAL MULTIMETER

KS–AHM–32–003

ECM

TEST HARNESS

07LAJ–PT3010A

1. Connect the Test Harness between the ECM and connector (see section 11).
2. Set the digital multimeter to check voltage between D11 (+) terminal and D22 (-) terminal for the throttle posi- tion sensor.ProCarManuals.com

Upshift

Downshift

3. Accelerate to about 35 mph (57 km/h) so the transmission is in 4th, then shift to . The car should immediately

begin slowing down from engine braking.

CAUTION: Do not shift from to at speed over 76 mph (123 km/h): from to at speed over 45 mph (73

km/h); you may damage the transmission.

(1st Gear)

1. Accelerate from a stop at full throttle. Check that there is no abnormal noise or clutch slippage.

2. Upshifts should not occur with the selector in this range.

(2nd Gear)

1. Accelerate from a stop at full throttle. Check that there is no abnormal noise or clutch slippage.

2. Upshifts and downshifts should not occur with the selector in this range.

(3rd Gear)

Accelerate from a stop at full throttle. Check that there is no abnormal noise or clutch slippage.

(Reverse)

Accelerate from a stop at full throttle, and check for abnormal noise and clutch slippage.

(Park)

Park car on a slope (approx. 16°), apply the parking brake, and shift into Park. Release the brake; the car should not

move.ProCarManuals.com

Stall Speed

Test

CAUTION:

To prevent transmission damage, do not test stall speed for more than 10 seconds at a time.

Do not shift the lever while raising the engine speed.

Be sure to remove the pressure gauge before testing stall speed.

1. Engage the parking brake and block all four wheels.

2. Connect the tachometer, and start the engine.

3. Make sure the A/C switch is OFF.

4. After the engine has warmed up to normal operating temperature (the cooling fan comes on), shift into position.

5. Fully depress the brake pedal and accelerator for 6 to 8 seconds, and note engine speed.

6. Allow 2 minutes for cooling, then repeat same test in and position.

NOTE:

Stall speed tests should be used for diagnostic pressure only.

Stall speed should be the same in and

Stall Speed RPM: Specification:
1,950-2,250
rpmProCarManuals.com

Fluid Level

Checking/Changing

Checking

NOTE: Check the fluid level with the engine at nor-

mal operating temperature (the cooling fan comes

on).

1. Park the car on level ground. Turn off the engine.

2. Remove the dipstick (yellow loop) from the

transmission, and wipe it with a clean cloth.

NOTE: Check the fluid level for to 90 seconds

from 60 seconds after the engine had shut off.

3. Insert the dipstick into the transmission.

4. Remove the dipstick, and check the fluid level. It

should be between the upper and lower marks.

5. If the level is below the lower mark, add fluid into

the tube to bring it to the upper mark. Use Honda

Premium Formula Automatic Transmission Fluid or

an equivalent DEXRON® II Automatic Transmission

Fluid (ATF) only.

6. Insert the dipstick back into the transmission.

UPPER

LOWER

DIPSTICK

(YELLOW LOOP)

DRAIN PLUG

50 N·m (5.0 kg-m, 36 Ib-ft)

SEALING WASHER

Replace.
Changing

1. Bring the transmission up to operating temperature

by driving the car. Park the car on level ground, turn

the engine off, then remove drain plug.

2. Reinstall the drain plug with a new washer, then refill

the transmission to the full mark on the dipstick.

Automatic Transmission Fluid Capacity:

2.9 (3.1 US qt., 2.6 Imp. qt.) at change

7.0 (7.4 US qt., 6.2 Imp. qt.) after overhaul

6.3 (6.7 US qt., 5.5 Imp. qt.) after overhaul

with new torque

converter.ProCarManuals.com

Pressure Testing

A/T LOW PRESSURE A/T OIL PRESSUREGAUGE W/PANEL HOSE ADAPTER

07406–0070300 07MAJ–PY40120
1. Allow the rear wheels to rotate freely.

2. Run the engine at 2,000 rpm.

3. Shift the select lever as shown on the chart on
the next page.
4. Measure each clutch pressure.
While testing, be careful of the rotating
rear wheels.

4. Start the engine and measure the respective pressure
as follows.
Line Pressure/Clutch Pressure
Clutch Low/High Pressure
Throttle B Pressure

5. Install a new washer and the sealing bolt in the
inspection hole and tighten to the specified torque.

Torque: 18 N .
m (1.8 kg-m, 13 Ib-ft)

NOTE: Do not reuse old aluminum washers.

While testing, be careful of the rotating rear wheels.
Make sure lifts are placed properly (see section 1).
CAUTION: Before testing, be sure the transmission fluid is filled
to the proper level.
Warm up the engine before testing.
1. Raise the car. (see section 1).
2. Warm up the engine, then stop the engine and connect a tachometer.
3. Connect the oil pressure gauge to each inspection
hole(s).

18 N .
m (1.8 kg-m, 12 Ib-ft)
CAUTION: Connect the oil pressure gauge
securely, being sure not to allow dust and other
foreign particles to enter the inspection hole.

A/T PRESSURE A/T PRESSURE
GAUGE SET W/PANEL HOSE, 2210 mm
07406–0020400 07MAJ–PY4011A Line Pressure/Clutch Pressure MeasurementProCarManuals.com

1ST-HOLD CLUTCH PRESSURE

INSPECTION HOLE

2ND CLUTCH PRESSURE

INSPECTION HOLE

4TH CLUTCH PRESSURE

INSPECTION HOLE

LINE PRESSURE/ 1ST CLUTCH

PRESSURE INSPECTION HOLE

3RD CLUTCH PRESSURE

INSPECTION HOLE

(cont'd)ProCarManuals.com

Pressure Testing

(cont'd)

Clutch Low/High Pressure Measurement

While testing, be careful of the rotat-

ing rear wheels.

-1. Allow the rear wheels to rotate freely.

-2. Start the engine and let it idle.

-3. Shift the select lever to position.

-4. Slowly press down the accelerator pedal to in-

crease engine rpm until pressure is indicated on

the oil pressure gauge. Then release the acceler-

ator pedal, allowing the engine return to an idle,

and measure the pressure reading.
-5. With the engine idling, press down the acceler-

ator pedal approximately 1/2 of its possible trav-

el and increase the engine rpm until pressure is

indicated on the gauge, measure the highest

pressure reading obtained.

-6. Repeat steps-4 and -5 for each clutch pressure

being inspected.

2ND CLUTCH PRESSURE

INSPECTION HOLE

3RD CLUTCH PRESSURE

INSPECTION HOLE
4TH CLUTCH PRESSURE

INSPECTION HOLEProCarManuals.com

LINEAR SOLENOID
THROTTLE B

INSPECTION HOLE
LINEAR SOLENOID

CONNECTOR
View from terminal side.
LINEAR SOLENOID
Throttle B Pressure Measurement

While testing, be careful of the rotat-

ing rear wheels.

-1. Allow the rear wheels to rotate freely.

-2. Disconnect the linear solenoid connector.

-3. Shift the select lever to position.

-4. Run the engine at 1,000 rpm.

-5. Measure full opened throttle B pressure.

-6. Connect battery voltage to the linear solenoid ter-

minal of the connector.

-7. Measure full closed throttle B pressure.

PRESSUREProCarManuals.com

Transmission
Removal
Make sure lifts are placed properly, and

hoist brackets are attached to correct position (see sec-

tion 1).
CAUTION: Use fender covers to avoid damaging painted

surfaces.

1. Check and record the rear camber. (see section 18.)
2. Disconnect the battery negative (-) first, and positive (+) cable from the battery.
3. Drain automatic transmission fluid (ATF). Reinstall the drain plug with a new washer.
NOTE: Removing the ATF level gauge will allow the
ATF to drain more rapidly. 4. Remove the strut bar.
5. Remove the air cleaner housing.
6. Remove the connectors from the control box and remove the control box (see section 11).
CAUTION: Do not remove the vacuum tubes from
the control box.
7. Remove the wire harness holder, disconnect the vehicle speed sensor (VSS) wire connectors,
solenoid valve wire connectors, starter motor
cables and transmission ground cable.
8. Remove the ATF cooler as it is connected by the
hoses.

CAUTION: Do not remove the hoses from the ATF

cooler.

9. Remove the starter motor mounting bolts, then remove the starter motor.
10. Remove the transmission housing bolts and the transmission mounting bolts.
MAINSHAFT SPEED SENSOR
CONNECTOR
LOCK-UP CONTROL
SOLENOID VALVE
CONNECTOR
STARTER MOTOR
TRANSMISSION

HOUSING BOLTS
CONTROL BOX
STARTER MOTOR
STARTER MOTOR
MOUNTING BOLT
ATF COOLER
ATF COOLER FILTER/GASKET Replace.

VSS

CONNECTOR
COUNTERSHAFT SPEED SENSOR
CONNECTOR
LINEAR SOLENOID
CONNECTOR

SHIFT CONTROL

SOLENOID VALVE
CONNECTOR
GROUND CABLE
TRANSMISSION

MOUNTING BOLTS
TRANSMISSION

HANGER
Corrosion resistant bolt/nut

CABLEProCarManuals.com

(cont'd)
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.

PARKING BRAKE

CABLE HOLDER
PARKING BRAKE

CABLE
Corrosion resistant bolt/nut

Replace.
SELF-LOCKING NUT

REAR BEAM ROD
GASKET

Replace.

SELF-LOCKING NUT

Replace.

FRONT EXHAUST

PIPE A

14. Remove the parking brake cable holder and the wheel sensor wire clamp.

15. Make a reference mark on the flange of the adjusting bolt, adjusting cam and lower control arm.

16. Separate the toe control arm from the side beam.

17. Remove the damper fork bolt.

18. Separate the lower control arm from the side beam.

19. Remove the right driveshaft from the intermediate shaft.

DAMPER FORK BOLT

PARKING BRAKE

CABLE HOLDER

WHEEL SENSOR

WIRE CLAMP

LOWER CONTROL ARM

SELF-LOCKING NUT

Replace.
SIDE BEAM

TOE CONTROL ARM

SELF-LOCKING

NUT

Replace.

ADJUSTING BOLT
ADJUSTING CAM
Corrosion resistant bolt/nutProCarManuals.com