sensor ACURA NSX 1997 Service Owner's Guide
[x] Cancel search | Manufacturer: ACURA, Model Year: 1997, Model line: NSX, Model: ACURA NSX 1997Pages: 1503, PDF Size: 57.08 MB
Page 591 of 1503
Drive B y Wir e Syste m
System Descriptio n
The Driv e B y Wir e Syste m is a n electroni c throttl e contro l system .
Thi s syste m consist s of the throttl e valv e contro l moto r an d Throttl e Positio n (TP ) senso r assemble d i n Throttl e Bod y (TB) ,
th e accelerato r positio n sensor , an d th e Engin e Contro l Modul e (ECM) .
Driv e B y Wir e Syste m Functions :
Idl e Contro l Functio n
Whe n th e engin e i s idling , th e EC M control s th e throttl e valv e contro l moto r t o maintai n th e prope r idl e spee d accordin g
t o engin e loads .
Acceleratio n Contro l Functio n
Whe n th e accelerato r peda l i s depressed , th e EC M open s th e throttl e valv e dependin g o n th e accelerato r positio n senso r
signals .
(cont'd)
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Page 592 of 1503
Drive By Wire System
System Description (cont'd)
Cruise Control Function
The ECM controls the throttle valve control motor to maintain the set speed when the cruise control system is operating.
The throttle valve control motor takes the place of the cruise control actuator.
Traction Control System (TCS) Function
If wheel spin occurs during acceleration or cornering, the TCS control unit requests the ECM to reduce the engine power
by retarding the ignition timing and closing the throttle valve. If the wheels lock during deceleration, the TCS control unit
signals the ECM to open the throttle valve.
Engine Protection Function
When the engine speed exceeds 8,000 rpm (M/T) or 7,500 rpm (A/T), the ECM controls the throttle valve, regardless of the
accelerator position, to protect the engine from over-revving.
Fail-safe Function
On this system, the ECM monitors the position of the accelerator pedal with a dual circuit type accelerator position sensor,
and monitors the operation of the throttle valve control motor with a Throttle Position (TP) sensor.
When an abnormality occurs in the system, the ECM restricts the operation of the throttle valve control motor to allow the
engine to continue to run.ProCarManuals.com
Page 610 of 1503
Fuel Suppl y Syste m
Fuel Injector s
Replacemen t
Do no t smok e durin g th e work . Kee p ope n flame s awa y fro m you r wor k area .
1 . Reliev e fue l pressur e (se e pag e 11-132 ).
2 . Remov e th e intak e manifol d covers .
3 . Disconnec t th e connector s fro m th e fue l injector s an d th e IA T sensor .
4 . Plac e a ra g o r sho p towe l ove r th e vacuu m hos e an d fue l retur n hose , the n disconnec t the m fro m th e fue l pres -
sur e regulator .
5 . Disconnec t th e fue l hos e fro m th e fue l rail .
6 . Remov e th e retaine r nut s fro m th e fue l rai l an d harnes s holder .
7 . Disconnec t th e fue l rail .
8 . Remov e th e fue l injector s fro m th e intak e manifold .
INTAKEMANIFOL DCOVERS
12 N- m(1.2 kgf-m ,8.7 Ibf-ft )
FUELPRESSUR EREGULATO R
O-RINGReplace .
CUSHIO N
RIN G
Replace .
SEAL RIN GReplace .
FUEL INJECTO R
INSULATO R
Replace.
9. Slid e ne w cushio n ring s ont o th e fue l injectors .
10 . Coa t ne w O-ring s wit h clea n engin e oil , an d pu t the m o n th e fue l injectors .
11 . Inser t th e fue l injector s int o th e fue l rai l first .
12 . Coa t ne w sea l ring s wit h clea n engin e oil , an d pres s the m int o th e intak e manifold .
FUEL RAI L
HARNES SHOLDER
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Page 611 of 1503
13. To prevent damage to the O-rings, install the fuel injectors in the fuel rail first, then install them in the intake mani-
fold.
FUEL
RAILS
FUEL RAIL
INSULATOR
FUEL RAIL
14. Align the center line on the connector with the mark on the fuel rail.
15. Install and tighten the retainer nuts.
16. Connect the fuel hose to the fuel rail.
17. Connect the vacuum hose and fuel return hose to the fuel pressure regulator.
18. Install the connectors on the fuel injectors and the IAT sensor.
19. Install the intake manifold covers.
20. Turn the ignition switch ON (II), but do not operate the starter. After the fuel pump runs for approximately two seconds,
the fuel pressure in the fuel line rises. Repeat this two or three times, then check whether there is any fuel leakage.
MARKINGSProCarManuals.com
Page 622 of 1503
Intake Ai r Syste m
System Descriptio n
The syste m supplie s ai r fo r al l engine needs. I t consist s o f th e intak e ai r pipe . Ai r Cleane r (ACL) , intak e ai r duct , throttl e
body , an d intak e manifold . A resonato r i n th e intak e ai r duc t provide s additiona l silencin g a s ai r i s draw n int o th e system .
IAB CONTRO L
SOLENOI D VALV E
To No . 5 BACK-U P LIGHT S
ALTERNATO R TUR N SIGNAL S
(1 5 A ) FUS E
IABCONTRO L
DIAPHRAG M
THROTTLE INTAK E
VALV E AI R DUC T
VARIOU SSENSOR S
ACL
IABCONTRO LVALVE
INTAK E
MANIFOL DRESONATO R
IABCHEC KVALV E
IABVACUU MTANK
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Page 624 of 1503
Intake Air System
Throttle Cable ———
Inspection/Adjustment
1. Remove the accelerator position sensor cover.
2. Check that the throttle cable operates smoothly with
no binding or sticking. Repair as necessary.
3. Check cable free play at the throttle linkage. Cable
deflection should be 10 - 12 mm (0.39 - 0.47 in.).
ACCELERATOR
POSITION
SENSOR COVER
DEFLECTION
10-12
mm
(0.39
-
0.47
in.
LOCKNUT
CABLE
BRACKET
ADJUSTING NUT
4. If deflection is not within specs, loosen the locknut,
turn the adjusting nut until the deflection is as spec-
ified then retighten the locknut.
Installation
1. Rotate the throttle linkage counterclockwise, then
install the throttle cable in the throttle linkage and
install the cable housing in the cable bracket.
THROTTLE LINKAGE
CABLE
BRACKET
INNER
WIRE
LOCKNUT
ADJUSTING
NUT
2. Hold the cable sheath, removing all slack from the
cable.
3. Turn the adjusting nut until it is 3 mm (0.12 in.)
away from the cable bracket.
4. Tighten the locknut. The cable deflection should now
be 10 - 12 mm (0.39 - 0.47 in.). If not, see inspection/
adjustment.
LOCKNUT
9.8 N-m
(1.0 kgf-m,
7.2 Ibf-ft)
ADJUSTING
NUT
CABLE
BRACKET
3 mm
(0.12 in.)ProCarManuals.com
Page 626 of 1503
Intake Air System
Throttle Body (cont'd)
Disassembly
THROTTLE BODY
IDLE ADJUSTING
SCREW
O-RING
Replace.
INTAKE AIR DUCT
THROTTLE VALVE
CONTROL MOTOR
TP SENSORProCarManuals.com
Page 628 of 1503
Intake Air System
Intake Air Bypass (IAB) Control System
Description
Satisfactory power performance is achieved by closing and opening the intake air bypass (IAB) control valves. High torque
at low engine speed is achieved when the valves are closed, whereas high power at high engine speed is achieved when
the valves are opened.
INTAKE AIR BYPASS (IAB) CONTROL
SOLENOID VALVE ON
ENGINE SPEED IS ABOVE 4,800 rpm
OPEN: HIGH ENGINE SPEED
CLOSED: LOW ENGINE SPEED
IAB CONTROL
SOLENOID
VALVE
To No. 5 BACK-UP LIGHTS
ALTERNATOR TURN SIGNALS
(15 A) FUSE
IAB
CONTROL
DIAPHRAGM
•IAB
CONTROL
VALVE
IAB
CHECK
VALVE
IAB
VACUUM
TANK
VARIOUS
SENSORSProCarManuals.com
Page 634 of 1503
Exhaust Gas Recirculation (EGR) System
The EGR system is designed to reduce oxides of nitrogen emissions (NOx) by recirculating exhaust gas through the EGR
valve and the intake manifold into the combustion chambers. It is composed of the EGR valve, EGR vacuum control valve,
EGR control solenoid valve, ECM and various sensors.
The ECM contains memories for ideal EGR valve lifts for varying operating conditions. The EGR valve lift sensor detects
the amount of EGR valve lift and sends the information to the ECM. The ECM then compares it with the ideal EGR valve lift
which is determined by signals sent from the other sensors. If there is any difference between the two, the ECM varies cur-
rent to the EGR control solenoid valve to regulate vacuum applied to the EGR valve.
EGR
VALVE
LIFT
SENSOR
INTAKE
MANIFOLD
EGR
CONTROL
SOLENOID
VALVE
To No. 5 BACK-UP
LIGHTS ALTERNATOR
TURN SIGNALS
(15 A) FUSE
-EGR
VACUUM
CONTROL
VALVE
(cont'd)
EGR
VALVE
VARIOUS
SENSORSProCarManuals.com
Page 636 of 1503
Evaporative Emission (EVAP) Controls
Description
The evaporative emission controls are designed to minimize the amount of fuel vapor escaping to the atmosphere. The
system consists of the following components:
A. Evaporative Emission (EVAP) Control Canister
An EVAP control canister is used for the temporary storage of fuel vapor until the fuel vapor can be purged from the
EVAP control canister into the engine and burned.
B. Vapor Purge Control System
EVAP control canister purging is accomplished by drawing fresh air through the EVAP control canister and into a port
on the throttle body. The purging vacuum is controlled by the EVAP purge control solenoid valve.
C. Fuel Tank Vapor Control System
When fuel vapor pressure in the fuel tank is higher than the set value of the EVAP two way valve, the valve opens and
regulates the flow of fuel vapor to the EVAP control canister.
From No. 5 BACK-UP
LIGHTS ALTERNATOR
TURN SIGNALS (15 A)
FUSE
FUEL TANK
EVAP VALVE
EVAP
BYPASS
SOLENOID
VALVE
VARIOUS
SENSORS
EVAP CONTROL
CANISTER
VENT SHUT VALVE
FUEL
TANK
PRESSURE
SENSOR
EVAP
TWO WAY
VALVE
EVAP CONTROL
CANISTER
EVAP PURGE
CONTROL
SOLENOID VALVE
(cont'd)
FUEL FILL
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