1991 LEXUS SC400 fuel pressure

VSV for Fuel Pressure Control
FI±90 ± Electronic Control System (VSV for Fue\
l Pressure Control)EFI SYSTEM
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COMPONENTS FOR REMOVAL AND INSTALLATION
FI±91EFI SYSTEM ± Electronic Control System (VSV for Fuel Pressure Control)
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INSPECTION OF VSV FOR FUEL
PRESSURE CONTROL
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
2. REMOVE VSV (a) Disconnect the VSV connector.
(b) Disconnect the following hoses from VSV:(1) Vacuum hose (from fuel pressure regulator)
(2) Vacuum hose (from air intake chamber)
(c) (Exc. USA Spec.) Remove the bolt holding the water by±pass pipe to the
VSV.
(d) Remove the bolt and VSV.
FI±92
EFI SYSTEM
± Electronic Control System (VSV for Fuel Pressure Control)
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3. INSPECT VSV
A. Inspect VSV for open circuitUsing an ohmmeter, check that there is continuity between
the terminals.
Resistance (Cold): 37±44

If there is no continuity, replace the VSV.
B. Inspect VSV for ground Using an ohmmeter, check that there is no continuity be-
tween each terminal and the body.
If there is continuity, replace the VSV.
C. Inspect VSV operation (a) Check that air flows from ports E to G.
(b) Apply battery voltage across the terminals.
(c) Check that air flows from ports E to the filter.
If operation is not as specified, replace the VSV.
4. REINSTALL VSV (a) Install the VSV with the bolt.
Torque: 18 N Vm (185 kgf Vcm, 13 ft Vlbf)
FI±93EFI SYSTEM ± Electronic Control System (VSV for Fuel Pressure Control)
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(b) (Exc. USA Spec.)Install the water by±pass pipe to the VSV with the bolt.
(c) Connect the following hoses to VSV: (1) Vacuum hose (from fuel pressure regulator)
(2) Vacuum hose (from air intake chamber)
(d) Connect the VSV connector.
5. RECONNECT CABLE TO NEGATIVE TERMINAL OF BATTERY
FI±94
EFI SYSTEM
± Electronic Control System (VSV for Fuel Pressure Control)
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TERMINALS OF ENGINE & ECT ECU (Cont'd)
TerminalNo.SymbolConnectionTerminalNo.SymbolConnection
E10± 21NCOT/M Input Speed SensorE10 ± 51±
22±52HTL2LH Sub±Oxygen Sensor Heater
23SP2No.2 Speed Sensor for ECT53HTR2RH Sub±Oxygen Sensor Heater
24±54±
25G2LH (No.2) Cam Position Sensor55±
26G1RH (No.1) Cam Position Sensor56IGT2No.2 Igniter for RH Bank
27NEEngine Speed Sensor57IGT1No.1 Igniter for LH Bank
28VF2Check Connector58IGF1No.1 Igniter for LH Bank
29VF1Check Connector59IGF2No.2 Igniter for RH Bank
30±60±
31±61±
32ISC4ISC Valve62±
33ISC3ISC Valve63IDL2Sub±Throttle Position Sensor
34ISC2ISC Valve64IDL1Throttle Position Sensor
35ISC1ISC Valve65E2Sensor Ground
36* EGR4EGR Valve66KSAir Flow Meter
37* EGR3EGR Valve67OXR2
38* EGR2EGR Valve68OXL2LH Sub±Oxygen Sensor
39* EGR1EGR Valve69E1ECU Ground39* EGRVSV for EGR69E1ECU Ground
40±70±
41VCThrottle Position Sensor
Air Flow Meter71HTL1LH Main Oxygen Sensor
42VTA2Fuel Pump ECU72HTR1RH Main Oxygen Sensor
43VTA1A/C Magnet Clutch Relay73FPUVSV for Fuel Pressure Control
Value
44THWWater Temp. Sensor74* PA GVSV for EVAP
45THAIntake Air Temp. Sensor75±
46THGEGR Gas Temp. Sensor76NSWNeutral Start Switch
47OXR1RH Main Oxygen Sensor77STAStarter Relay
48OXL1LH Main Oxygen Sensor78STJCold Start Injector
49KNK2RH (No.2) Knock Sensor79E02Power Ground
50KNK1LH (No.1) Knock Sensor80E01Power Ground
Engine & ECT ECU Terminals
*USA spec. only
*  A/T only
FI±127EFI SYSTEM ± Electronic Control System (Engine & ECT ECU)
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SERVICE SPECIFICATIONS
SERVICE DATA
Fuel pumpResistance0.2 ± 3.0

Cold start
injectorResistance
Fuel leakage2 ± 4

One drop or less per minute
Fuel pressure
regulatorFuel pressureat no vacuum265 ± 304 kPa
(2.7 ± 3.1 kgf/cm2, 38 ± 44 psi)
InjectorResistance
Injection volume
Difference between each cylinder
Fuel leakage13.4 ± 14.2

55 ± 70 cc (3.4 ± 4.3 cu in.) per 15 sec.
10 cc (0.6 cu in.) or less
One drop or less per minute
Air flow meterResistance (THA ± E2)at±20 °C (±4 °F)
at 0 °C (32 °F)
at 20 °C (68 °F)
at 40 °C (104 °F)
at 60 °C (140 °F)
at 80 °C (176 °F)10 ± 20 k

4 ± 7 k

2 ± 7 k

0.9 ± 1.3 k

0.4 ± 0.7 k

0.2 ± 0.4 k

Throttle bodyThrottle body fully closed angle6°
Throttle
positionClearance between
stop screw and leverBetween terminalsResistance
sensor
(main)0 mm
0.40 mm
0.65 mm0 in.
0.016 in.
0.026 in.VTA1 ± E2 IDL1 ± E2
IDL1 ± E2
VTA1 E2
0.2 ± 0.8 k

2.3 k
or less
Infinity
33 100k
Throttle valve fully opened position
±VTA1 ± E2VC ± E2
y
3.3 ± 10.0 k

4.0 ± 9.0 k

Sub±throttle
positionClearance between
stop screw and leverBetween terminalsResistance
sensor
(w/ TRAC)0 mm
0.30 mm
0.50 mm0 in.
0.012 in.
0.020 in.VTA2 ± E2 IDL2 ± E2
IDL2 ± E2
VTA2 E2
0.2 ± 0.8 k

2.3 k
or less
Infinity
33 100k
Throttle valve fully opened position
±VTA2 ± E2VC ± E2
y
3.3 ± 10.0 k

4.0 ± 9.0 k

Sub±throttle
actuator
(w/ TRAC)Resistance (ACM ± A and A, BCM ± B and B)0.5 ± 1.0

ISC valveResistance (B1 ± S1 and S3, B2 ± S2 and S4)10 ± 30

Cold start
injector time
switchResistance STA ± STJ below 15 °C (59 °F)
above 30 °C (86 °F)
STA ± Ground25 ± 45

65 ± 85
25 ± 85

VSV for fuel
pressure
controlResistance37 ± 44

FI±137 ± Service SpecificationsEFI SYSTEM
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TORQUE SPECIFICATIONS
Part tightenedNVmkgf Vcmft Vlbf
Fuel line Union bolt type
Flare nut type2930022
Fuel pipe X Delivery pipe39400 29
Fuel pump bracket X Fuel tank5.455 48 in.Vlbf
Fuel pump set plate X Fuel tank3.940 35 in. Vlbf
Fuel tank X Body25250 18
Fuel sender gauge X Fuel tank2.930 26 in. Vlbf
Fuel inlet pipe X Fuel tank2.930 26 in. Vlbf
Fuel tank main tube X Fuel tank29300 22
Fuel tank return tube X Fuel tank29300 22
Fuel tank evaporation vent tube X Fuel tank29300 22
Air flow meter X Air cleaner case10100 7
Cold start injector X Air intake chamber7.880 69 in. Vlbf
Cold start injector tube X Cold start injector15150 11
Air intake chamber X Intake manifold18185 13
EGR pipe X Air intake chamber18185 13
EGR pipe X RH cylinder head18185 13
Cold start injector tube X RH Delivery pipe15150 11
Throttle body X Air intake chamber18185 13
Fuel return pipe X Fuel pressure regulator35360 26
Fuel pressure regulator X RH delivery pipe29300 22
Delivery pipe X Intake manifold18185 13
Fuel inlet hose X LH delivery pipe39400 29
for SST33340 24
ISC valve X Air intake chamber18185 13
Cold start injector time switch X Front water by±pass joint34350 25
Water temperature sensor X Front water by±pass joint20200 14
Water inlet housing X Water pump18185 13
EGR gas temperature sensor X EGR valve adaptor20200 14
EGR valve adaptor X Air intake chamber18185 13
EGR valve X EGR valve adaptor18185 13
Knock sensor X Cylinder block44450 33
Intake manifold X Cylinder head18185 13
Main oxygen sensor X Exhaust manifold44450 33
Sub±oxygen sensor X Exhaust manifold4445033
FI±142EFI SYSTEM ± Service Specifications
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