Engine Controls - Adjustments Lexus ES V20

ENGINE COMPRESSION

Warm engine to normal operating temperature. Remove air intake chamber. Disconnect distributor connector. Remove spark plugs. Ensure battery is fully charged. Check engine compression with throttle fully open and engine cranking at specified cranking RPM.

ENGINE COMPRESSION TEST

Scheme 1

Scheme 2

1. With engine cold, disconnect negative battery cable. Drain engine coolant. On automatic transmission models, disconnect throttle cable from throttle body and bracket. Disconnect accelerator cable and bracket from throttle body and air intake chamber.
2. Disconnect airflow meter connector and air hoses. Loosen air cleaner hose clamp bolt. Release air cleaner cover clips and remove air cleaner cap and airflow meter together with air cleaner hoses.
3. Remove the following hoses: PCV, water by-pass, vacuum sensing, fuel pressure VSV and emission control vacuum control hoses. Disconnect ISC, throttle position sensor and EGR gas temperature sensor connectors.
4. Remove 3 bolts and right engine mounting stay. Disconnect cold start injector and tube. Disconnect brake booster vacuum and cruise control vacuum hoses. Remove ground strap connector. Remove nut and wire harness. Disconnect EGR pipe.
5. Remove 2 bolts and engine hanger. Remove bolt and disconnect air intake chamber stay from air intake chamber. Remove 2 bolts, nuts, air intake chamber and gasket. Remove cylinder head covers.
6. Rotate crankshaft pulley and align pulley groove with "0" mark on timing belt cover to position No. 1 cylinder at TDC of compression stroke. Ensure cylinder No. 1 intake valve lifters are loose and exhaust valve lifters are tight. If not, rotate crankshaft 360 degrees and realign timing marks.
7. Measure and record clearance of intake valves on cylinders No. 1 and 6, and exhaust valves on cylinders No. 2 and 3. (Scheme 1) Rotate crankshaft pulley 240 degrees (2/3 of a revolution). Measure and record clearance of intake valves on cylinders No. 2 and 3, and exhaust valves on cylinders No. 4 and 5.
8. Rotate crankshaft pulley another 240 degrees (2/3 of a revolution). Measure and record clearance of intake valves on cylinders No. 4 and 5, and exhaust valves on cylinders No. 1 and 6.
9. Determine if clearance is within specification. See VALVE CLEARANCE SPECIFICATIONS TABLE. If clearance adjustment is required, rotate crankshaft pulley to position lobe upward on the valve to be adjusted.
10. Use Valve Clearance Adjuster (SST 09248-55011) to press valve lifter downward. Prior to pressing lifter downward, position adjustment shim notch area toward the spark plug.
11. Press valve lifter downward using SST (A) and install SST (B) between camshaft and valve lifter and remove SST (A). (Scheme 2) Using a small screwdriver and magnet, remove adjustment shim.
12. Using a micrometer, measure thickness of shim just removed. Select a new shim that will give correct valve clearance. See VALVE CLEARANCE SPECIFICATIONS TABLE. Shims are available in thickness of.0984-.1299" (2.50-3.30 mm) in.002" (.05 mm) increments.
13. Install proper shim. Using SST (A), press downward on valve lifter and remove SST (B). Recheck valve clearance. Install air intake chamber using new gaskets. Tighten air intake chamber bolts to 32 ft. lbs. (43 N.m) and EGR pipe to 58 ft. lbs. (78 N.m). Install remaining components.
14. Air must be bled from cooling system while filling cooling system. To bleed air from cooling system, open union bolt (bolt closest to upper radiator hose on radiator hose outlet on intake manifold) approximately 5 revolutions. Fill cooling system and tighten union bolt to 13 ft. lbs. (18 N.m).

VALVE CLEARANCE SPECIFICATIONS

IGNITION TIMING

Scheme 3

1. Ensure engine is at normal operating temperature. Connect timing light to engine. Connect tachometer to "IG-" terminal of engine check connector.
2. Install jumper wire between terminals "TE1" and "E1"of engine check connector. (Scheme 3) Ensure idle speed is within specification. See IDLE SPEED SPECIFICATIONS TABLE in this article. Note that base timing is within specification. See IGNITION TIMING TABLE. Adjust timing by turning distributor.
3. Remove jumper wire from engine check connector and check that advance timing is within specification. See IGNITION TIMING TABLE.

IGNITION TIMING

IDLE SPEED & MIXTURE

Note. Mixture adjustment IS NOT a part of normal tune-up procedure and should only be performed when mixture control unit is replaced or vehicle fails emissions testing.

IDLE SPEED

Note. Idle speed is controlled by the computer and idle speed control system.

1. Install tachometer to proper terminals. Start engine and note if idle speed is within specification. See IDLE SPEED SPECIFICATIONS TABLE.
2. If idle speed is not within specification, check the ISC valve, wiring and ECU. See IDLE SPEED CONTROL (ISC) SYSTEM in SYSTEM/COMP TESTS article in the ENGINE PERFORMANCE Section.

IDLE SPEED SPECIFICATIONS

IDLE MIXTURE

Note. Idle mixture must be checked with air cleaner installed, all air intake system hoses and vacuum lines connected, EFI system wiring connectors tight, transmission/transaxle in Neutral, all accessories and cooling fan off (if equipped) and engine at normal operating temperature.

1. Ensure idle speed is within specification. Install jumper wire between proper terminals of check engine connector. Connect positive (+) probe of voltmeter to terminal "VF" or "VF1" and negative (-) probe to terminal "E1". (Scheme 3)
2. Start engine and maintain engine RPM at 2500 RPM for approximately 2 seconds. With engine RPM at 2500, count the amount of times that voltmeter fluctuates between the specified voltage. See IDLE MIXTURE TEST SPECIFICATIONS TABLE.
3. If the amount of fluctuations is less than the minimum amount, check for air leaks at the air induction system, defective airflow meter or throttle body.
4. If fluctuations were within specification, accelerate and hold engine at 2500 RPM for approximately 2 minutes. Install exhaust gas analyzer probe in tailpipe at least 1.3 feet. Wait one minute and check idle mixture readings. If readings are not within specification, see IDLE MIXTURE TROUBLE SHOOTING TABLE.

IDLE MIXTURE TEST SPECIFICATIONS

IDLE MIXTURE TROUBLE SHOOTING

IDLE MIXTURE TROUBLE SHOOTING

Scheme 4

1. Loosen TPS mounting screws. Unplug TPS and connect ohmmeter between throttle position sensor "IDL" and "E2" terminals. (Scheme 4) Insert a.020" (.50 mm) feeler gauge between throttle stop screw and lever.
2. Rotate TPS clockwise until ohmmeter deflects. Tighten mounting screws. Using specified feeler gauge, recheck adjustment. See THROTTLE POSITION SENSOR ADJUSTMENT TABLE. Remove ohmmeter and connect TPS.

THROTTLE POSITION SENSOR ADJUSTMENT

THROTTLE POSITION SENSOR ADJUSTMENT

DASHPOT CONTROL SYSTEM

For testing and adjustment procedures, see DASHPOT CONTROL SYSTEM in SYSTEM/COMP TESTS article in the ENGINE PERFORMANCE Section.