1991 ACURA NSX service

Starter Brush Holder Test

1. Check that there is no continuity between the

and brush holders.

If continuity exists, replace the brush holder

assembly.

BRUSH HOLDER

BRUSH HOLDER

BRUSH HOLDER

2. Insert the brush into the brush holder, and bring the

brush into contact with the commutator, then at-

tach a spring scale to the spring. Measure the

spring tension at the moment the spring lifts off the

brush.

Spring Tension:

18.0-24.0 N (1.80-2.40 kg, 4.0-5.3 Ibs)

SPRING SCALE

BRUSH
SPRING
Starter Brush Inspection

Measure the brush length. If not within the service limit,

replace the armature housing and brush holder

assembly.

Brush Length

Standard (New):
15.0-15.5
mm
(0.591
-0.610
in)

Service Limit: 10.0 mm (0.394 in)

BRUSH

NOTE: To seat new brushes after installing them in

their holders, slip a strip of #500 or #600 sandpaper,

with the grit side up, over the commutator, and

smoothly rotate the armature. The contact surface of

the brushes will be sanded to the same contour as the

commutator.
BRUSH HOLDERProCarManuals.com

Starting System

Armature Inspection and Test

1. Inspect the armature for wear or damage due to

contact with the field coil magnets.

Inspect for

damage.

2. A dirty or burnt commutator surface may be resur-

faced with emery cloth or a lathe within the follow-

ing specifications.

Commutator Diameter

Standard (New):
29.9-30.0
mm

(1.177-1.181 in)

Service Limit: 29.0 mm (1.142 in)

VERNIER CALIPER

COMMUTATOR
Commutator Runout

Standard (New): 0—0.02
mm
(0-0.0008
in)

Service Limit: 0.05 mm (0.002 in)

DIAL

INDICATOR

COMMUTATOR

3. If the commutator runout and diameter are within

limits, check the commutator for damage or for car-

bon dust or brass chips between the segments.

4. If the surface is dirty, recondition it with a #500 or

#600
sandpaper. Then, check mica depth.
If

necessary, undercut mica with a hacksaw blade to

achieve proper depth.

COMMUTATOR

SANDPAPER

MICA DEPTH

Commutator Mica Depth

Standard (New):
0.5-0.8
mm
(0.02-0.03
in)

Service Limit: 0.2 mm (0.008 in)ProCarManuals.com

Ignition System
Component Local

IGNITION TIMING CONTROL SYSTEM
Description, page 23-89
Inspection, page 23-91 ('94-'96) ('91-'93).
Troubleshooting, section 11

NOISE CONDENSER

Test, page 23-97
SPARK PLUG (6)

Inspection, page 23-96
TEST TACHOMETER CONNECTOR
SERVICE CHECK

CONNECTOR (2-P)
(Connector color: BLU)
CRANKSHAFT POSITION/CYLINDER POSITION

(CKP/CYP) SENSOR
Troubleshooting, section 11
Replacement, section 5
IGNITION COIL (6)
Removal, page 23 94
('94-'96) ('91-'93) Test, page 23-95.
('94-'96) ('91-'93)
IGNITION CONTROL MODULE (ICM)
Replacement, page 23-92

Input Test, page 23-93
Troubleshooting, section 11
SERVICE LOOP
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Ignition Timin g Inspectio n
SRS component s ar e locate d in thi s area . Revie w th e SR S
componen t locations , precautions , an d procedure s in th e
SR S sectio n 24 befor e performin g repair s o r service .
1 . Pul l ou t th e servic e chec k connecto r locate d unde r
th e middl e o f th e dash . Connec t th e BL U an d BRN /
BL K terminal s wit h th e SC S servic e connector .
2 . Star t th e engine . Hol d th e engin e a t 3,00 0 rp m wit h
n o loa d (A/ T i n [N ] o r 0 position , M/ T i n neutral )
unti l th e radiato r fa n come s on , the n le t i t idle .
NOTE : I f yo u sto p th e engin e o r tur n th e ignitio n
switc h OF F afte r warm-u p wit h th e SC S servic e con -
necto r connected , th e engin e wil l idl e a t th e bas e
idl e speed . Tha t is , i t wil l no t b e controlle d b y th e
ECM . T o retur n t o th e norma l idl e speed , pres s th e
accelerato r peda l on e time .
SERVIC E CHEC K CONNECTO R (2-P )
SCS SERVIC E CONNECTO R07PAZ - 001010 0
3. Chec k th e idl e spee d (se e pag e 23-92 ).
4 . Connec t a timin g ligh t t o th e servic e loop ; whil e th e
engin e idles , poin t th e ligh t towar d th e pointe r o n
the timin g bel t cover .
SERVIC E LOO P
TIMIN G LIGH T
5. Chec k th e ignitio n timing .
Ignitio n Timing : 15 ° + 2° BTD C (RE D mark )
Idl e Spee d (rpm) :
NOTE : Al l electrica l system s ar e turne d OFF .
POINTE R
WHITE MAR K
RED MAR K
CRANKSHAF T PULLE Y
6. I f i t i s necessar y to adjus t th e ignitio n timing , replac e
the ECM .
7. Remov e th e SC S servic e connecto r fro m th e servic e
check connector .
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Rectifier Test

NOTE: The diodes are designed to allow current to

pass in one direction while blocking it in the opposite

direction. Since the alternator rectifier is made up of

eight diodes (four pairs), each diode must be tested for

continuity in both directions with an ohmmeter that has

diode checking capability; a total of sixteen checks.

1. Check for continuity in each direction, between the

B and P, and between the E (ground) and P ter-

minals of each diode pair. All diodes should have

continuity in only one direction.

E (GROUND)

2. If any of the eight diodes fails, replace the rectifier

assembly. (Diodes are not available separately.)
Alternator Brush Inspection

1. Remove the end cover, then take out the brush

holder by removing its two screws.

2. Measure the length of the brushes with a vernier

caliper.

Alternator Brush Length:

Standard: 10.5 mm (0.41 in)

Service Limit: 3.5 mm (0.14 in)

ALTERNATOR BRUSHES

VERNIER CALIPER

If the brushes are less than the service limit,

replace the assembly.ProCarManuals.com

Gauge Assembly
Gauge/Terminal Location Index
SRS components are located in this area. Review the SRS component locations, precautions, and procedures in the SRS

section (24) before performing repairs or service.

SPEEDOMETER:

Indicates 60 mph [60km/h] at 1.026 [637]

rpm of the vehicle speed sensor (VSS).
FUEL GAUGE: Gauge test, page 23-134 Sending Unit Test, page 23-135

VOLTAGE METER:
If, with the No. 5 (15 A) fuse

and other gauges

OK, the pointer of the

voltage meter does not move at all,
replace the voltage

meter.

SAFETY INDICATOR SYSTEM:
See page 23-145 ('93-'96) ('91-'92)A/T GEAR POSITION
INDICATOR SYSTEM:
See page 23-156 ENGINE OIL PRESSURE
GAUGE:
Test page 23-137
ENGINE COOLANT TEMPERATURE (ECT) GAUGE:
Gauge Test, page 23-136 Sender Test, page 23-136
TACHOMETER:

Indicates 100 rpm at 300 pulses per minute

of the igniter unit.ProCarManuals.com

Gauge Assembl y
Removal
SRS component s ar e locate d in thi s area . Revie w th e SR S
componen t locations , precautions , an d procedure s i n th e
SR S sectio n 24 befor e performin g repair s o r service .
1 . Remov e th e dashboar d lowe r cover , an d disconnec t
th e floo r wir e harnes s connectors .
2 . Remov e th e tw o screws , the n remov e th e dashboar d
lowe r pa d fro m th e dashboard .
DASHBOAR DLOWER
COVE R
DASHBOAR DLOWER PA D
3. Remov e the thre e screws , then remov e the tilt cove r
fro m th e steerin g column .
TILT COVE R
4. Disconnec t th e connector s fro m th e instrumen t
pane l switches .
5 . Remov e th e si x screws , the n remov e th e instrumen t
pane l tri m fro m th e dashboard .
INSTRUMEN T PANE L TRI M
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Interlock System

Component Location Index
SRS components are located in this area. Review the SRS component locations, precautions, and procedures in the SRS

section (24) before performing repairs or service.
TCS CONTROL UNIT

INTERLOCK CONTROL UNIT
Input Test, page 23-142
A/T GEAR POSITION SWITCH
Test, page 23-160

Replacement, page 23-161 ('93-'96)('91-'92)

KEY INTERLOCK SOLENOID
and KEY INTERLOCK SWITCH (In the steering lock assembly)
Test, page 23-143 SHIFT LOCK SOLENOID
Test, page 23-144
Replacement, page 23-144ProCarManuals.com