Engine Controls - Adjustments - v6 Toyota 4Runner II

ENGINE MECHANICAL

Before performing any on-vehicle adjustments to fuel or ignition systems, ensure engine mechanical condition is okay.

CAMRY

1. Check and adjust valves with engine cold. Remove valve covers. 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 valve lifters are not as described, rotate crankshaft 360 degrees and realign timing marks.
2. Measure and record clearance of intake valves on cylinders No. 1 and 6, and exhaust valves on cylinders No. 2 and 3. (Scheme 24) 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.
3. 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.
4. Ensure clearance is within specification. Refer to the «VALVE CLEARANCE SPECIFICATIONS TABLE (CAMRY)»(/toyota/4runner/ii-1987-1995/remont/adjustments/#engine-controls-adjustments-v6). If clearance adjustment is required, rotate crankshaft pulley so camshaft lobe is facing upward on valve to be adjusted.
5. Position adjusting shim notch toward spark plug. Use Valve Clearance Adjuster (SST 09248-55010) and SST (A) to press valve lifter downward. (Scheme 25) Install SST (B) between camshaft and valve lifter. Remove SST (A). Using a small screwdriver and magnet, remove adjusting shim.
6. Using micrometer, measure thickness of shim removed. Determine correct thickness of replacement shim to be used by subtracting appropriate valve clearance specification (Refer to the «VALVE CLEARANCE SPECIFICATIONS TABLE (CAMRY)»(/toyota/4runner/ii-1987-1995/remont/adjustments/#engine-controls-adjustments-v6) from measured valve clearance. Add this number to thickness of old shim. Select a new shim with a thickness as close as possible to the calculated value. See appropriate «SHIM THICKNESS TABLE (CAMRY)»(/toyota/4runner/ii-1987-1995/remont/adjustments/#engine-controls-adjustments-v6).
7. Install proper shim. Using SST (A), press downward on valve lifter and remove SST (B). Recheck valve clearance. Install valve cover.

Scheme 24

Scheme 25

VALVE CLEARANCE SPECIFICATIONS

SHIM THICKNESS

PICKUP & 4RUNNER

1. Check and adjust valves with engine cold. Remove valve covers. Rotate crankshaft pulley and align pulley groove with "0" mark on timing belt cover to set cylinder No. 1 at TDC of compression stroke.
2. Ensure cylinder No. 1 valve lifters are loose and cylinder No. 4 valve lifters are tight. If valve lifters are not as described, rotate crankshaft 360 degrees and realign timing marks.
3. Measure and record clearance of exhaust valve on cylinder No. 2, and intake valve on cylinder No. 6. (Scheme 26) Rotate crankshaft pulley 120 degrees (1/3 of a revolution). Measure and record clearance of intake valve on cylinder No. 1, and exhaust valve on cylinder No. 3.
4. Rotate crankshaft pulley 120 degrees (1/3 of a revolution). Measure and record clearance of intake valve on cylinder No. 2, and exhaust valve on cylinder No. 4.
5. Rotate crankshaft pulley 120 degrees (1/3 of a revolution). Measure and record clearance of intake valve on cylinder No. 3, and exhaust valve on cylinder No. 5. Rotate crankshaft pulley another 120 degrees (1/3 of a revolution). Measure and record clearance of intake valve on cylinder No. 4, and exhaust valve on cylinder No. 6.
6. Rotate crankshaft pulley 120 degrees (1/3 of a revolution). Measure and record clearance of intake valve on cylinder No. 5, and exhaust valve on cylinder No. 1.
7. Ensure clearance is within specification. Refer to the «VALVE CLEARANCE SPECIFICATIONS TABLE (PICKUP & 4RUNNER)»(/toyota/4runner/ii-1987-1995/remont/adjustments/#engine-controls-adjustments-v6). If clearance adjustment is required, rotate crankshaft pulley so camshaft lobe is facing upward on the valve to be adjusted.
8. Position adjusting shim notch area in the direction in which the shim will be removed. Use Valve Clearance Adjuster (SST 09248-55010) and SST (A) to press valve lifter downward. (Scheme 25) Install SST (B) between camshaft and valve lifter. Remove SST (A). Using a small screwdriver and magnet, remove adjusting shim.
9. Using micrometer, measure thickness of shim removed. Determine correct thickness of replacement shim to be used by subtracting appropriate valve clearance specification (Refer to the «VALVE CLEARANCE SPECIFICATIONS TABLE (PICKUP & 4RUNNER)»(/toyota/4runner/ii-1987-1995/remont/adjustments/#engine-controls-adjustments-v6) from measured valve clearance. Add this number to thickness of old shim. Select a new shim with a thickness as close as possible to the calculated value. See «SHIM THICKNESS TABLE (PICKUP & 4RUNNER)»(/toyota/4runner/ii-1987-1995/remont/adjustments/#engine-controls-adjustments-v6).
10. Install proper shim. Using SST (A), press downward on valve lifter and remove SST (B). Recheck valve clearance. Install valve cover.

Scheme 26

VALVE CLEARANCE SPECIFICATIONS

SHIM THICKNESS

IGNITION TIMING

1. Ensure engine is at normal operating temperature. Connect timing light to engine. Connect tachometer to proper location. (Scheme 27)and (Scheme 28).
2. Install jumper wire between proper terminals of engine check connector. (Scheme 29)and (Scheme 30). Ensure idle speed is within specification. See appropriate «IDLE SPEED SPECIFICATIONS»(/toyota/4runner/ii-1987-1995/remont/adjustments/#engine-controls-adjustments-v6) table under IDLE SPEED & MIXTURE. Ensure base timing is within specification. See «IGNITION TIMING»(/toyota/4runner/ii-1987-1995/remont/adjustments/#engine-controls-adjustments-v6) table.
3. Adjust timing by turning distributor.
4. Remove jumper wire from engine check connector and ensure advance timing is within specification. See «IGNITION TIMING»(/toyota/4runner/ii-1987-1995/remont/adjustments/#engine-controls-adjustments-v6) table. Tighten distributor hold-down bolt. See «TORQUE SPECIFICATIONS»(/toyota/4runner/ii-1987-1995/remont/adjustments/#engine-controls-adjustments-v6) table at end of article.

IGNITION TIMING

Scheme 27

Scheme 28

Scheme 29

Scheme 30

IDLE MIXTURE

Note. Idle mixture adjustment is not possible on any model. See appropriate G - TESTS W/ CODES article in this section for diagnosis of incorrect idle mixture.

IDLE SPEED

CAMRY 2.5L

Note. Idle speed on Camry 2.5L is controlled by the computer and idle speed control system.

1. Install tachometer to proper terminals. (Scheme 27) Start engine and check if idle speed is within specification. Refer to the «IDLE SPEED SPECIFICATIONS»(/toyota/4runner/ii-1987-1995/remont/adjustments/#engine-controls-adjustments-v6) table.
2. If idle speed is not within specification, check the Idle Speed Control (ISC) valve, wiring and ECU. See IDLE CONTROL SYSTEMS in appropriate I - SYS/COMP TESTS article in this section.

PICKUP 3.0L & 4RUNNER 3.0L

1. Install tachometer to proper terminals. (Scheme 28) Start engine and operate at 2500 RPM for about 2 minutes. Check if idle speed is within specification. See «IDLE SPEED SPECIFICATIONS»(/toyota/4runner/ii-1987-1995/remont/adjustments/#engine-controls-adjustments-v6) table.
2. If idle speed requires adjustment, adjust idle speed adjusting screw to obtain correct idle speed. Remove tachometer.

IDLE SPEED SPECIFICATIONS

THROTTLE POSITION SENSOR (TPS)

Note. Vehicles with Electronically Controlled Transaxle (ECT) use signals sent from TPS to Electronic Control Unit (ECU) to calculate gear shift and lock-up timing.

1. Loosen mounting screws. Unplug TPS connector. Connect ohmmeter between terminals IDL and E2. (Scheme 31)and (Scheme 32).
2. To set initial clearance, insert proper thickness feeler gauge between throttle stop screw and throttle lever. See appropriate «THROTTLE POSITION SENSOR ADJUSTMENT»(/toyota/4runner/ii-1987-1995/remont/adjustments/#engine-controls-adjustments-v6) table.
3. With ohmmeter showing infinity, rotate TPS clockwise until continuity exists. Tighten mounting screws. Using specified feeler gauge, recheck adjusted clearance. Disconnect ohmmeter and reconnect TPS after adjustment.

THROTTLE POSITION SENSOR ADJUSTMENT

Scheme 31

Scheme 32

DASHPOT CONTROL SYSTEM

For testing and adjustment procedures, see THROTTLE CONTROLS under EMISSION SYSTEMS & SUB-SYSTEMS in appropriate I - SYS/COMP TESTS article in this section.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• VALVE CLEARANCE SPECIFICATIONS TABLE (CAMRY)