Engine Controls (Removal & Installation): Overhaul Lexus SC II

Disassembly & Reassembly (ES300)

Disconnect fuel pump connector. Pull off lower side of fuel pump from pump bracket. see scheme 47 Disconnect fuel hose from fuel pump. Remove fuel pump from fuel pump assembly bracket. Remove rubber cushion from fuel pump. Remove retaining clip and pull fuel pump screen from fuel pump. To reassemble, reverse disassembly procedure.

Disassembly & Reassembly (GS300, GS430, IS300, LS430, RX300 & SC430)

1. Using 2 small screwdrivers, pry off No. 2 fuel suction support. see scheme 50 Ensure not to damage suction supports. Remove suction support rubber cushion. Disconnect fuel return jet tube from clamp of No. 2 suction support. Pull out fuel pressure regulator from in tank fuel filter and remove fuel pressure regulator and fuel return jet tube assembly. Remove "O" ring from fuel pressure regulator.
2. Remove clip and remove fuel pump screen. Using 2 small screwdrivers, pry off No. 1 fuel suction support. Ensure not to damage suction support. Remove No. 2 fuel filter cushion. Disconnect fuel pump connector. see scheme 50
3. Using a pulling motion, remove fuel filter and fuel pump assembly. see scheme 50 Remove No. 1 fuel filter cushion. Remove "O" ring from fuel port of fuel suction plate. Using a pulling motion, remove fuel pump from fuel filter.
4. To reassemble, reverse disassembly procedure. Apply a light coat of gasoline to NEW "O" rings. Install NEW fuel pump assembly gasket and fuel pump screen retaining clip.

Disassembly & Reassembly (LX470)

1. Disconnect lead wire from top of fuel pump. Pull bottom of fuel pump from fuel pump mounting bracket. Disconnect fuel hose at top of fuel pump. Remove fuel pump with rubber cushion from fuel pump mounting bracket. see scheme 53
2. Remove rubber cushion from bottom of fuel pump. Using small screwdriver, remove retaining clip that holds fuel filter on bottom of fuel pump. Remove fuel filter from fuel pump. To reassemble, reverse disassembly procedure using NEW retaining clip on fuel filter.

Disassembly (ES300)

If necessary to remove throttle position sensor, remove 2 set screws and throttle position sensor.

Reassembly (ES300)

1. To install throttle position sensor, ensure throttle valve is under condition of opener opening angle (about 6 degrees). Install sensor to position where it is 20-30 degrees rotated to right from its installation position. (Scheme 74) Gradually turn sensor counterclockwise until it touches throttle valve shaft and temporarily tighten 2 set screws. (Scheme 75)
2. Connect throttle position sensor connector. Connect OBD-II scan tool to DLC3. Turn ignition on. DO NOT depress accelerator pedal. While reading throttle valve opening percentage, turn throttle position sensor slowly to left and right and set sensor at center value of standard value of 16-17.6 percent. (Scheme 75) Recheck throttle valve opening percentage. If throttle valve opening percentage is not to specification, repeat this step. If throttle valve opening percentage is to specification, go to next step.
3. Operate fully closed throttle valve by hand and check that throttle valve opening percentage of CURRENT DATA on scan tool stays within standard value of 10-14 percent. If opening percentage is not as specified, repeat step 2. If opening percentage is to specification, apply paint on 2 set screws. Turn ignition off. Disconnect scan tool. Disconnect throttle position sensor connector.

Scheme 74

Scheme 75

Disassembly (GS300 & IS300)

1. If necessary to remove Throttle Position (TP) sensor, remove retaining screws and TP sensor from throttle body. (Scheme 76)
2. If necessary to remove throttle control motor, ensure TP sensor is removed from throttle body. Disconnect electrical connector for throttle control motor from wiring bracket. (Scheme 76) Remove retaining screws and cover to access throttle control motor. Remove retaining screws and throttle control motor from throttle body.
3. If necessary to remove accelerator pedal position sensor, using small screwdriver, bend tabs on washer plate away from retaining screws for accelerator pedal position sensor. (Scheme 76) Remove retaining screws, washer plate and accelerator pedal position sensor from throttle body.

Scheme 76

Reassembly (GS300 & IS300)

1. Install accelerator pedal position sensor, washer plate and retaining screws on throttle body. Tighten retaining screws to specification in sequence. see scheme 66 See «TORQUE SPECIFICATIONS»(ref-151794-S13416371322003010800000). Bend tabs on washer plate against retaining screws.
2. To check accelerator pedal position sensor operation after installation on throttle body, install electrical connector on accelerator pedal position sensor.
3. Connect scan tool to Data Link Connector (DLC) No. 3 located under left side of instrument panel. Turn ignition on. DO NOT depress accelerator pedal after ignition is turned on. Using scan tool, check that ACCEL POS#1 (VPA) voltage of the CURRENT DATA is.3-.9 volt. This is the standard accelerator pedal position sensor voltage. Turn ignition off. Disconnect electrical connector for accelerator pedal position sensor.
4. To install throttle control motor, ensure all gears on throttle control motor and throttle body are clean. Apply thin coat of grease on the entire surface of the gear teeth on the throttle body. Install throttle control motor on throttle body. Ensure holes on throttle control motor align with pins on throttle body.
5. Rotate throttle control motor clockwise and install retaining screw "A". see scheme 67 Ensure throttle control motor is tight against the pins on throttle body. Install remaining retaining screws in throttle control motor. Tighten retaining screws to specification. See «TORQUE SPECIFICATIONS»(ref-151794-S13416371322003010800000).
6. Install cover and retaining screws. Ensure grommet on throttle control motor is not pinched. Tighten cover retaining screws to specification. See «TORQUE SPECIFICATIONS»(ref-151794-S13416371322003010800000). Reinstall electrical connector for throttle control motor on wiring bracket.
7. To install TP sensor, ensure throttle valve opening on throttle body is about 3.5 degrees. Install TP sensor on throttle body so it is at position No. 1 (30 degrees). Rotate TP sensor counterclockwise to position No. 2 until it contacts throttle valve. see scheme 68 Install retaining screws.
8. To check TP sensor adjustment, reinstall electrical connector on TP sensor. Connect scan tool to Data Link Connector (DLC) No. 3 under left side of instrument panel. Turn ignition on. NOTE: Ensure accelerator pedal is not depressed after turning ignition on when adjusting TP sensor.
9. Use scan tool to read throttle valve opening which is displayed as a percentage. Throttle valve opening may be read by accessing THROTTLE POS under CURRENT DATA on scan tool.
10. While reading throttle valve opening, rotate TP sensor counterclockwise (toward throttle control motor on throttle body) until throttle valve opening is 14.8 percent, as this is the center of the standard throttle valve opening of 14.0-15.6 percent. Tighten TP sensor retaining screws to specification. See «TORQUE SPECIFICATIONS»(ref-151794-S13416371322003010800000). NOTE: When TP sensor retaining screws are tightened, this may cause the throttle valve opening to change. Ensure throttle valve opening remains between 14.0-15.6 percent after TP sensor retaining screws are tightened. Readjust TP sensor if necessary.
11. Using screwdriver, fully close throttle valve on throttle body. Use scan tool to read throttle valve opening by accessing THROTTLE POS under CURRENT DATA on scan tool. With throttle valve fully closed, throttle valve opening should be 10-14 percent.
12. If throttle valve opening is not within specification with throttle valve fully closed, repeat steps 9 - 11 until correct throttle valve opening is obtained. Turn ignition off. Remove scan tool.

Disassembly (GS430, LS430 & SC430)

To remove TP sensor, remove 2 sensor retaining screws. Remove sensor. No other disassembly instructions are provided by manufacturer.

Reassembly (GS430, LS430 & SC430)

1. To install TP sensor, ensure throttle valve opening on throttle body is 4 degrees or less. Install sensor on throttle body so it is at position No. 1 (15 degrees). (Scheme 77)
2. Rotate TP sensor clockwise to position No. 2 until it contacts throttle valve. (Scheme 77) Install and tighten retaining screws to specification. See «TORQUE SPECIFICATIONS»(ref-151794-S13416371322003010800000).
3. To check TP sensor operation after installation on throttle body, install electrical connector on TP sensor. Connect scan tool to Data Link Connector (DLC) No. 3 under left side of instrument panel.
4. Turn ignition on. DO NOT depress accelerator pedal after ignition is turned on. Using scan tool, check that THROTTLE POS of the CURRENT DATA is 14.4-16.0 percent. If reading is not as specified, loosen and rotate TP sensor until reading is within middle of specified range. Retighten screws.

Scheme 77

Disassembly (RX300)

1. If necessary to remove Throttle Position (TP) sensor, remove TP sensor retaining screws and TP sensor from throttle body. see scheme 73
2. If necessary to remove Idle Air Control (IAC) valve, remove IAC valve retaining screws, bracket, IAC valve and gasket. If necessary to replace throttle bodies, remove protector, clip and plate washer. Disconnect accelerator link. Remove 6 throttle body retaining screws, No. 1 throttle body, No. 2 throttle body and 2 gaskets from No. 1 intake air control valve.

Reassembly (RX300)

To install TP sensor, ensure throttle valve is fully closed. Place TP sensor on throttle body with TP sensor turned clockwise 30-60 degrees against the fully closed throttle valve. Turn sensor clockwise until TP sensor mounting holes line up with throttle body mounting holes. Install and tighten TP sensor retaining screws. To install IAC valve, use a NEW IAC valve gasket. Position IAC valve on throttle body. Install and tighten IAC valve screws.