1991 ACURA NSX Service Repair Manual

Ignition Timing Inspection and Setting

1. Start the engine and allow it to warm up (radiator
fan comes on).
2. Pull out the service check connector located under the middle of the dash. Connector the BLU andGRN/WHT terminals with a jumper wire (see sec-

tion 11).

3. Check the idle speed (see page 23-92).
4. Connect a timing light to the service loop; while the
engine idles, point the light toward the pointer on

the timing belt cover.
SERVICE LOOP

TIMING LIGHT

5. If necessary, adjust ignition timing to the following specifications:
Ignition Timing: 15° ±2° BTDC (RED mark)
Idle Speed (rpm):
NOTE: All electrical systems turned OFF. POINTER
RED MARK
CRANKSHAFT PULLEY
WHITE MARK
6. If necessary, adjust the ignition timing, adjust by turning the adjusting screw on the ignition timingadjuster in the control box.
Remove the control box cover. 7. Remove the jumper wire from the service check
connector.
8. After adjusting, reinstall the cover on the ignition timing adjuster with new rivets.ADJUSTING SCREW
To ADVANCE
To RETARD Reconnect the adjuster to the car, start the
engine, and turn the adjusting screw
counterclockwise to retard the timing, or
clockwise to advance it, as necessary.
CAUTION: Do not damage the adjuster when
removing the rivets. Remove the ignition timing adjuster from the
control box.

Drill the two rivets off with a 3/16 in. drill bit,

then separate the cover from the adjuster. 3-P CONNECTORCONTROL BOX

IGNITION TIMING

ADJUSTER
Remove the two screws from the control box
then disconnect the 3-P connector from the igni-

tion timing adjuster.ProCarManuals.com

Ignition System

Ignition Coils/Spark Plugs Removal

CAUTION:

Ignition coils and spark plugs can become very hot in

use, do not touch them until the engine has cooled

down.

1. Remove the ignition coil covers.

2. Disconnect the 2-P connectors from the ignition

coils.

3. Remove the ignition coils.

4. Remove the spark plugs.

IGNITION COIL COVER

IGNITION COIL

VALVE COVER
PLATINUM TIP SPARK PLUG
RUBBER

SEAL
2-P CONNECTOR
NOTE: Different ignition coils and ignition coil

covers are used for the front and rear cylinders. Be

sure to use the correct ones when mounting them.ProCarManuals.com

Ignition Coil Test

1. With the ignition switch OFF, remove the ignition

coil.

2. Using an ohmmeter, measure resistance between

the terminals. Replace the coil if the resistance is

not within specifications.

NOTE: Resistance will vary with the coil

temperature; specification is at 77°F (25°C).

Primary Winding Resistance

(Between the A and B terminals): 0.9—1.1 ohms

3. If primary winding resistance is OK, substitute a

known-good ignition coil and check the system

operation.

If the system is normal, replace the original ignition

coil.
A TERMINAL

B TERMINAL

IGNITION

COIL

SECONDARY

WINDING

TERMINAL

SECONDARY

WINDING

TERMINALProCarManuals.com

Charging System
Alternator Overhaul
NOTE: It is only necessary to separate the pulley, drive

end housing and rotor when the front bearing needs

replacement.

Loosen the locknut with 10 mm and 22 mm wrenches

to remove the pulley from the rotor. If necessary, use an
impact wrench.

TERMINAL INSULATOR
END COVER BRUSH HOLDER
22 mm BOX

WRENCH
VOLTAGE REGULATOR
BRUSH HOLDER
INSULATOR
SPACER RING
REAR BEARING
BRUSHES

Inspection, page 23-107

DIODE (RECTIFIER) ASSEMBLY

Test, page 23-107

INSULATOR SLEEVE
BEARING RETAINER STATOR THROUGH BOLT
Do not disassemble.

STATOR ASSEMBLY/DRIVE END HOUSING

Test, page 23-108

PULLEY LOCKNUT
115 N .
m

(11.5kg-m, 83 Ib-ft)

PULLEY

FRONT BEARING
ROTOR

Test, page 23-108

CAUTION: Do not get grease

or oil on the slip rings.
PULLEY

10 mm BOX WRENCH
PULLEY LOCKNUT 115 N .
m (11.5 kg-m, 83 Ib-ft)
REAR HOUSING ASSEMBLYProCarManuals.com

Radiator and Condenser Fan Controls
Component Location Index
UNDER HOOD RELAY BOX A
RADIATOR FAN
RESISTOR

Test, page 23-116

RIGHT CONDENSER
FAN MOTOR
Test, page 23-117
Replacement, see section 22
RADIATOR FAN MOTOR
Test, page 23-117Replacement, see section 5 LEFT CONDENSER FAN
MOTOR
Test, page 23-117

Replacement, see section 22
A/C TRIPLE PRESSURE
SWITCH

See, section 22

CLIMATE CONTROL UNIT

Troubleshooting, see section 22

RADIATOR FAN

LOW RELAY

Wire colors: WHT/BLU,
YEL/BLK, RED and GRN/BLK
RADIATOR FAN
HIGH RELAY

Wire colors: WHT/BLU
BLK, YEL/BLK and BLU/RED
CONDENSER FAN RELAY
Wire colors: WHT/GRN, BLK,
YEL/BLK and ORN/BLUProCarManuals.com

ECM

RADIATOR FAN CONTROL SENSOR

Test, page 23-120
ENGINE COMPARTMENT FAN MOTOR

Test, page 23-118
Replacement, page 23-118
ENGINE COMPARTMENT

FAN RELAY

Wire colors: YEL/BLU
BLK/YEL, WHT/RED,
and WHT/BLU

Test, page 23-119

FAN CONTROL

UNITProCarManuals.com

Troubleshooting

NOTE: The numbers in the table show the troubleshooting sequence.
Refer to section 22 for A/C pressure inspection of the A/C system.ProCarManuals.com

Gauge Assembly

Bulb Locations

SRS INDICATOR LIGHT (1.4W)

EPS INDICATOR LIGHT (1.4 W)

RIGHT TURN SIGNAL INDICATOR LIGHT (1.4 W)

BRAKE SYSTEM LIGHT (1.4W)

SEAT BELT REMINDER LIGHT (1.4W)

TCS-OFF INDICATOR

LIGHT (1.96 W)

LOW FUEL INDICATOR

LIGHT (1.4W)

GAUGE LIGHT

(1.4W)

GAUGE LIGHT

(3.0W)
CRUISE LIGHT

(1.96W)

GAUGE LIGHT

(3.0W)
TCS ACTIVATION

INDICATOR LIGHT

(1.96
W)

GAUGE LIGHT

(3.0W)
GAUGE LIGHT

(1.4W)
LOW OIL PRESSURE

INDICATOR

,LIGHT(1.4W)
MALFUNCTION

INDICATOR

LAMP (MIL)

(1.4W)
CHARGING SYSTEM LIGHT (1.4 W)
ABS

INDICATOR LIGHT (1.4 W)
LEFT TURN SIGNAL INDICATOR LIGHT (1.4 W)
TCS INDICATOR LIGHT (1.4W)
HIGH BEAM INDICATOR LIGHT (1.4W)
GAUGE LIGHTS (1.4W x 2)ProCarManuals.com