Engine Controls - Remove/install/overhaul Lexus ES XV10

INTRODUCTION

Removal, overhaul and installation procedures are covered in this article. If component removal and installation is primarily an unbolt and bolt-on procedure, only a torque specification may be furnished.

ENGINE CONTROL MODULE (ECM)

Removal & Installation

Ensure ignition is off. Remove ECM. See ECM LOCATION table. To install, reverse removal procedure.

ECM LOCATION

Removal

1. Disconnect airflow meter connector. Disconnect air hoses. Loosen air cleaner hose clamp bolt. Disconnect air cleaner cover clips. Remove air cleaner cover and airflow meter together with air cleaner hose.
2. Remove spark plug and coil wires. Disconnect distributor connector. Remove 2 hold-down bolts and distributor. Remove "O" ring.

Installation

1. Set No. 1 cylinder to TDC on compression stroke. Install new "O" ring onto distributor housing. Coat "O" ring with oil. Align cutout marks of coupling and housing. (Scheme 1) Install distributor, and lightly tighten hold-down bolts.
2. Reconnect spark plug and coil wires and distributor connector. Install airflow meter, air cleaner cover and hoses. Start engine and allow to warm up. Connect tachometer and timing light. Set timing to specification. See IGNITION TIMING in the «ADJUSTMENTS»(/lexus/es/xv10-1991-1994/remont/adjustments/#engine-controls-adjustments) article.

Scheme 1

1. Disconnect spark plug and coil wires from distributor cap. Set No. 1 cylinder to TDC on compression stroke.
2. Remove hold-down nut and pull distributor from head. Remove "O" ring seal from distributor shaft.

1. Install new "O" ring seal to distributor shaft and coat with oil. Align protrusion on drive gear with groove in distributor housing. Insert distributor, aligning stud in cylinder head with center of flange slot. (Scheme 2) Lightly tighten hold-down nut.
2. Connect spark plug and coil wires to distributor cap. Start engine, and warm it to normal operating temperature. Connect test probe of tachometer to terminal IG (-) of check connector. (Scheme 3) CAUTION: Never allow tachometer terminal to touch ground as it can cause damage to ignitor and/or ignition coil. Some tachometers are not compatible with ignition system. Confirm compatibility before using tachometer.
3. With a fused jumper wire, connect terminals TE1 and E1 of check connector. (Scheme 3) With all accessories off, check idle speed (700 RPM for M/T and 650 RPM for A/T). Using a timing light, adjust timing to 10 degrees BTDC (engine at idle and transmission in Neutral).
4. Disconnect jumper wire from check connector. Verify timing (9-11 degrees BTDC at idle, transmission in Neutral). Disconnect timing light and tachometer.

Scheme 2

Scheme 3

Scheme 4

1. To remove right distributor, remove air duct. Disconnect airflow meter connector. Loosen clamp bolt and disconnect air hose. Remove airflow meter assembly. Remove throttle body cover.
2. Disconnect ISC air hose, power steering idle-up air hose and 2 bolts and main air hose. Remove spark plug and coil wire cover. Remove spark plug wire cover from engine. Remove No. 3 timing belt cover and gaskets. (Scheme 4)
3. Disconnect sensor connector. Remove wire boot and No. 2 timing belt cover with 4 gaskets. (Scheme 4) Disconnect high tension wires from distributor cap. Remove distributor cap. Remove rotor. Remove distributor. Sensor can be removed at this time.
4. To remove left distributor, drain engine coolant. Remove engine wire cover. Remove junction block cover. Remove No. 3 timing belt cover with 4 gaskets. (Scheme 4) Disconnect coolant hoses from coolant inlet housing. Disconnect hoses from reservoir tank. Remove connector boot and No. 2 timing belt cover with 2 gaskets. (Scheme 4)
5. Remove spark plug wires from distributor. Remove distributor cap. Remove rotor. Remove distributor housing. Sensor can now be removed.

1. Reverse removal procedure. Refill and bleed cooling system. Start engine, and allow it to warm. Connect tachometer and timing light. Ensure timing is within specification. Refer to IGNITION TIMING in the «ADJUSTMENTS»(/lexus/es/xv10-1991-1994/remont/adjustments/#engine-controls-adjustments) article.
2. If timing is not within specification, ensure throttle valve is fully closed, continuity exists between throttle position sensor terminals IDL and E2 and valve timing is correct.

FUEL SYSTEM WARNING

FUEL SYSTEM PRESSURE RELEASE

To relieve fuel pressure, wrap cold start injector feed pipe banjo bolt using shop towel. Slowly loosen banjo bolt to relieve pressure. Pick up or dry any fuel which may have run onto engine.

1. Disconnect cold start injector connector. With an ohmmeter, measure resistance between terminals. If resistance is not 2-4 ohms, replace cold start injector. Disconnect cable from negative terminal of battery. CAUTION: If vehicle is equipped with air bag, DO NOT start work until 30 seconds or longer after ignition switch is turned to LOCK position and negative terminal cable has been disconnected from battery.
2. Using shop towels to absorb spilled fuel, remove union bolt slowly. When removing union bolt and injector pipe, DO NOT lose gaskets. Remove 2 nuts, cold start injector and gasket.

1. Install injector with a new gasket, and tighten to specification. See «TORQUE SPECIFICATIONS»(/lexus/es/xv10-1991-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul) table.
2. Using 2 new gaskets, connect injector pipe with union bolt and tighten to specification. See «TORQUE SPECIFICATIONS»(/lexus/es/xv10-1991-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul) table. Connect cold start injector connector. Connect cable to negative battery terminal. Check for fuel leaks.

COLD START INJECTOR (LS400)

1. Relieve fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(/lexus/es/xv10-1991-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-system-pressure-release) . Disconnect negative battery cable and drain engine coolant. Remove air cleaner with airflow meter. Remove throttle body and left side engine wire harness cover. Disconnect ISC valve electrical connector, cold start injector connector, EGR VSV connector and EGR gas temperature sensor connector.
2. Disconnect power steering idle-up hose from intake chamber. Disconnect brake booster hose from intake chamber. Disconnect PCV hose from EGR adapter, 3 vacuum hoses from air pipe, 2 vacuum hoses from EGR VSV and EGR vacuum modulator hoses. Remove EGR vacuum modulator. Remove air pipe. Disconnect coolant by-pass pipe.
3. Remove accelerator cable and bracket. Disconnect cold start injector fuel delivery pipe. Disconnect EGR pipe from air intake chamber and remove gasket. Remove 4 bolts, 8 nuts, throttle cable clamp, 2 VSVs, check connector and air intake chamber.
4. Disconnect cold start injector connector. Remove banjo bolt, cold start injector tube and 2 gaskets. Remove 2 bolts and cold start injector and gasket.

1. Install cold start injector with new gasket, and tighten to specification. See «TORQUE SPECIFICATIONS»(/lexus/es/xv10-1991-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul) table. Install cold start injector tube and banjo bolt with new gaskets, and tighten to specification. Install air intake chamber with new gaskets, and tighten to specification.
2. To complete installation, reverse removal procedure. Tighten nuts and bolts to specification. See «TORQUE SPECIFICATIONS»(/lexus/es/xv10-1991-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul) table. Fill cooling system with proper mix of water and coolant. Ensure cooling system is properly bled. Start engine, and inspect it carefully to ensure no fuel or coolant leaks exist.

FUEL PUMP (ES300)

1. Disconnect cable from negative battery terminal. Remove rear seat cushion. Disconnect fuel connector. With an ohmmeter, measure resistance between connector terminals No. 4 and No. 5. If resistance is not 0.2-3.0 ohms, replace fuel pump. Briefly (no more than 10 seconds) touch B+ to terminal 4 and ground to terminal 5. Replace pump if it does not operate.
2. Remove floor service hole cover. Disconnect pump connector, and remove lead wire and hole cover.
3. Disconnect outlet pipe from pump bracket. Disconnect return hose from pump bracket. Remove 8 bolts, and pull out pump bracket assembly. Remove gasket from pump bracket.

1. Install new gasket to pump bracket, and insert pump bracket assembly into fuel tank. Install 8 bolts, and tighten to specification. See «TORQUE SPECIFICATIONS»(/lexus/es/xv10-1991-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul) table.
2. Connect outlet pipe to pump bracket, and tighten to specification. See «TORQUE SPECIFICATIONS»(/lexus/es/xv10-1991-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul) table. Connect return hose(s) to pump bracket, and check for leakage.
3. Connect pump lead wire, and install service hole cover. Connect fuel pump connector. Install rear seat cushion. Connect cable to negative terminal of battery.

FUEL PUMP (LS400)

Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELEASE . Disconnect negative battery cable. Drain fuel from tank. Remove front luggage compartment cover. Remove rear seat back. Remove partition panel plug. Disconnect fuel pump electrical connector. Remove fuel pump assembly. To install, reverse removal procedure.

FUEL PUMP (SC300 & SC400)

1. Disconnect negative battery cable. Remove luggage compartment floor mat, spare tire and luggage compartment trim panel. Disconnect fuel pump connector.
2. Remove rear seat. Using a scraper, remove round partition cover. Remove eight set plate mounting bolts and disconnect fuel pump set plate from fuel tank.
3. Remove three nuts and disconnect fuel pump bracket from tank. Disconnect fuel hose from pump bracket and remove fuel pump, bracket and set plate assembly.

To install, reverse removal procedures. Use new gasket on fuel pump set plate and butyl sealer tape on partition cover.

1. Relieve fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(/lexus/es/xv10-1991-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-system-pressure-release) . Disconnect negative battery cable. Drain engine coolant. Disconnect throttle cable from throttle body and bracket (A/T). Disconnect accelerator cable and bracket from throttle body and air intake chamber.
2. Remove air cleaner cover, airflow meter and air cleaner hose. Disconnect PCV hoses, vacuum sensing hose, water by-pass hose, fuel pressure VSV hose, emission control vacuum hoses, ISC connector, throttle position sensor connector and EGR gas temperature sensor.
3. Remove right engine mounting stay. Disconnect cold start injector connector. Disconnect cold start injector tube banjo bolt. Disconnect brake booster vacuum hose, power steering vacuum and air hoses, cruise control vacuum hose, ground strap connector and wire harness clamp.
4. Disconnect EGR pipe. Remove engine hanger. Remove bolt, and disconnect air intake chamber stay from chamber. Remove 2 bolts, nuts, air intake chamber and gasket. Disconnect coolant temperature connector. Disconnect 6 injector connectors. Disconnect wire harness from left fuel rail.
5. Disconnect fuel return hose from fuel pressure regulator. Disconnect fuel inlet hose from fuel filter. Remove 2 banjo bolts, 4 gaskets and left fuel pipe. Remove fuel rail together with injectors. To remove injectors from fuel rail, pull using a slight twisting motion.

1. Install new "O" rings and grommets on injectors. Using a twisting motion, push injectors onto fuel rail. (Scheme 5) Put 6 insulators and 4 spacers in position on intake manifold. Place fuel rails and injectors in position on intake manifold. Install mounting bolts, and tighten to specification. See «TORQUE SPECIFICATIONS»(/lexus/es/xv10-1991-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul) table.
2. To complete installation, reverse removal procedure. See «TORQUE SPECIFICATIONS»(/lexus/es/xv10-1991-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul) table. Fill cooling system with proper mix of water and coolant. Turn ignition on. Using a jumper wire, connect terminals +B and FP of check connector. (Scheme 6) Pinch fuel return hose to raise fuel pressure in system. Inspect carefully to ensure no fuel leaks exist.

Scheme 5

Scheme 6

1. Relieve fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(/lexus/es/xv10-1991-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-system-pressure-release) . Disconnect negative battery cable. Wait at lease 20 seconds before proceeding with work. Drain engine coolant. Remove throttle body and intake air connector. Place container or shop towel under fuel rail and disconnect No. 1 fuel pipe.
2. Place container or shop towel under fuel pressure regulator and disconnect No. 2 fuel pipe from regulator. Remove air intake chamber brackets. Disconnect vacuum sensing hose from pressure regulator. Disconnect injector connectors.
3. Remove two bolts from control valve actuator. DO NOT disconnect rod clip from actuator. Secure actuator to intake chamber with tape. Remove three fuel rail mounting bolts and fuel rail along with 6 injectors. Remove six insulators and three spacers.

1. Install new grommets and "O" rings on injectors. Lubricate "O"-ring with light coat of gasoline and insert injectors on fuel rail using a twisting motion. Position injector connectors outward.
2. Place the six insulators and three spacers in position on intake manifold. Place fuel rail with injectors in position on cylinder head. Temporarily install fuel rail mounting bolts. Ensure that injectors rotate freely and position connector facing up.
3. Tighten three fuel rail mounting bolts to 15 ft. lbs. (21 N.m). Install control valve actuator and torque mounting bolts to 61 in. lbs. (6.8 N.m). Install Injector connectors, vacuum sensing hose and injector chamber brackets. Torque bracket mounting bolts to 13 ft. lbs. (18 N.m).
4. Connect No. 2 fuel pipe to fuel rail with new gaskets and torque union bolts to 20 ft. lbs. (27 N.m). Connect No. 1 fuel pipe to fuel rail with new gaskets and torque union bolts to 30 ft. lbs. (42 N.m). Install throttle body and intake air connector.

1. Relieve fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(/lexus/es/xv10-1991-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-system-pressure-release). Disconnect negative battery cable. To remove right side fuel injectors and fuel rail, remove air cleaner and airflow meter. Remove right and left engine wire covers. Remove right and left No. 3 timing belt covers. (Scheme 4) Remove high tension wire covers.
2. Remove engine wire harness from fuel rail. Disconnect coolant temperature gauge sender connector, coolant temperature sensor connector, cold start injector time switch connector and injector connectors. Disconnect fuel return pipe, cold start injector tube and front fuel pipe.
3. Remove 2 banjo bolts, 4 gaskets and rear fuel pipe. Leave rear fuel pipe on vehicle. Remove vacuum hose from fuel pressure regulator. Remove 2 nuts and fuel rail with injectors.
4. To remove left side fuel injectors and fuel rail, disconnect PCV hose. Remove high tension wire cover and engine wire cover. Disconnect 4 vacuum hoses from air pipe. Disconnect vacuum hose from BVSV, 2 hoses from EGR VSV and EGR vacuum modulator hose.
5. Remove EGR vacuum modulator with bracket. Disconnect check connector from bracket. Disconnect connectors from 2 VSVs, and then remove VSVs. Remove 2 coolant by-pass pipes. Disconnect engine wiring harness from fuel rail. Disconnect distributor connector, engine speed sensor connector, EGR gas temperature sensor connector and 4 injector connectors.
6. Remove bolt, pulsation damper and 2 gaskets. Disconnect fuel inlet hose from fuel rail. Disconnect front fuel pipe. Remove rear fuel pipe as outlined in step 3). Remove 2 nuts and fuel rail with injectors.

1. Install new "O" rings and grommets on injectors. Using a twisting motion, push injectors onto fuel rail. (Scheme 5) Install insulators into injector holes in intake manifold. Install injectors together with fuel rail, and lightly tighten nuts. Ensure injectors rotate smoothly left and right. If injectors do not rotate smoothly, recheck "O" ring installation.
2. To complete installation, reverse removal procedure. See «TORQUE SPECIFICATIONS»(/lexus/es/xv10-1991-1994/remont/removal-installation/#engine-controls-removeinstalloverhaul) table. Fill cooling system with proper mix of water and coolant. Ensure cooling system is properly bled. Start engine, and inspect it carefully to ensure no fuel or coolant leaks exist.

Oxygen (O2) sensor(s) mounting is in exhaust pipe(s), just below exhaust header(s). O2 sub-sensor(s) location (if equipped) is in exhaust pipe(s) behind TWC toward rear of vehicle. When removing sensor(s), ensure permanent pigtail is protected from damage. Ensure freedom from contaminants, and remove sensor(s) from exhaust pipe(s). Avoid using cleaning solvents of any type. If engine temperature is less than 120°F (48°C), sensor(s) may be difficult to remove. To install, apply anti-seize compound on sensor threads and tighten to specification. See TORQUE SPECIFICATIONS table.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• ADJUSTMENTS
• ECM LOCATION
• FUEL SYSTEM PRESSURE RELEASE