Engine Controls - Basic Testing: Other Lexus ES XV20

Compression

Check engine mechanical condition with a compression gauge, vacuum gauge, or an engine analyzer. See engine analyzer manual for specific instructions. To check engine compression with a compression gauge, bring engine to normal operating temperature. Disconnect fuel injector connectors. Remove ignition coils. Remove all spark plugs. Fully open throttle. Ensure engine cranking speed is at least 250 RPM when measuring compression. Repeat engine compression test procedure at least 2 times.

COMPRESSION SPECIFICATIONS

Exhaust System Backpressure (Using Pressure Gauge)

Remove front Heated Oxygen Sensor (HO2S). Connect a 0-5 psi pressure gauge and run engine at 2500 RPM. If exhaust system backpressure is more than 2 psi, exhaust system or catalytic converter is plugged.

Exhaust System Backpressure (Using Vacuum Gauge)

Connect vacuum gauge hose to intake manifold vacuum port and start engine. Observe vacuum gauge. Open throttle part way and hold steady. If vacuum gauge reading slowly drops after stabilizing, check for restricted exhaust system.

FUEL SYSTEM

ES300

Remove rear seat cushion. Remove fuel pump access cover. Disconnect fuel pump connector. Start and run engine until it stops. Place shop rag under fuel filter to catch any spilled fuel. Remove hose clamp securing fuel line to fuel filter. Slowly remove fuel line from fuel filter. With fuel pressure relieved, reinstall fuel line.

GS300, LS400, SC300 & SC400

Remove trunk floor mat. Remove trunk trim panel. Disconnect fuel pump connector. Start and run engine until it stops. Wrap fuel line connection at fuel rail with shop towel to catch any spilled fuel. Loosen banjo bolt enough to relieve any remaining fuel pressure. Tighten banjo bolt.

FUEL PRESSURE

1. Ensure battery is fully charged. Turn ignition off. Disconnect negative battery cable. On ES300, go to next step. On GS300 and SC300, go to step 3). On LS400 and SC400, go to step 4).
2. On ES300, place container under fuel filter. Cover fuel filter outlet banjo bolt with shop towel. Slowly loosen banjo bolt to relieve fuel pressure. Remove banjo bolt and gaskets. Go to step 5).
3. On GS300 and SC300, disconnect vacuum pipe from rear of air intake chamber (to access fuel hose). Cover fuel inlet hose banjo bolt (at fuel rail) with shop towel. Slowly loosen banjo bolt to relieve fuel pressure. Remove banjo bolt and gaskets. Go to step 5).
4. On LS400 and SC400, remove fuel pressure pulsation damper, located at rear of right fuel rail. Cover fuel inlet hose banjo bolt (at fuel rail) with shop towel. Slowly loosen banjo bolt to relieve fuel pressure. Remove banjo bolt and gaskets. Go to next step.
5. On ES300, install Fuel Pressure Gauge (SST 09268-45012). On all models except ES300, install Fuel Pressure Gauge (SST 09268-45014), gaskets and banjo bolt. On all models, tighten banjo bolt. Reconnect negative battery cable. Connect scan tool to Data Link Connector (DLC) No. 3. (Схема №1)
6. Using scan tool manufacturer's instructions, activate electric fuel pump and note fuel pressure. Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm 2 ). Remove scan tool from DLC No. 3. Start engine and allow to idle. Note fuel pressure. Fuel pressure should be 44-50 psi (3.1-3.5 kg/cm 2 ).
7. If fuel pressure exceeds specification, replace fuel pressure regulator. If fuel pressure is less than specified, check for defective fuel lines, connections, fuel pump, fuel filter, fuel pressure regulator or fuel pressure control Vacuum Switching Valve (VSV), if equipped.
8. Shut engine off and note fuel pressure. Fuel pressure should hold at least 21 psi (1.5 kg/cm 2 ) for a minimum of 5 minutes. If fuel pressure does not hold as specified, check for defective fuel pump, fuel injector or fuel pressure regulator. See SYSTEM/COMPONENT TESTS article.
9. Disconnect negative battery cable. Remove fuel pressure gauge. Reinstall banjo bolt using NEW gaskets. Tighten banjo bolt. Install negative battery cable.

IDLE SPEED & IGNITION TIMING

Ensure idle speed is set to specification. See IDLE SPEED SPECIFICATIONS table. Ensure ignition timing is set to specification. See IGNITION TIMING SPECIFICATIONS table. Idle speed and ignition timing are not adjustable. For checking procedures, see ADJUSTMENTS article.

SUMMARY

If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed to TESTS W/CODES article. If no hard codes are found in self-diagnostics, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.