ENGINE MECHANICAL
Before performing any on-vehicle adjustments to fuel or ignition systems, ensure engine mechanical condition is okay.
VALVE CLEARANCE
Note. Hydraulic lifters used. No adjustments are required.
IGNITION TIMING
- Start and warm engine to normal operating temperature. Ensure engine oil temperature is at least 176°F (80°C). Ensure A/C and electrical loads are off, including cooling fan.
- Ensure no Diagnostic Trouble Codes (DTC) are stored. Ensure throttle cable and closed throttle position switch are properly adjusted. Ensure idle air control valve is okay. Valve must vibrate or hum. Ensure exhaust system has no leaks.
- Disconnect Blue Engine Coolant Temperature (ECT) sensor wiring harness connector. Start engine and allow to idle. With timing light connected, check ignition timing. Timing mark is on flywheel. Timing pointer is on timing hole on transaxle bellhousing.
- If necessary, loosen distributor hold-down. Adjust ignition timing to 5-7 BTDC by rotating distributor. Ensure radiator cooling fan is not running during adjustment. Check and adjust idle speed if necessary. See «IDLE SPEED & MIXTURE»(ref-14570-S12708151362000122600000) .
- After adjustment, tighten distributor hold-down. To check ignition timing advance, ensure ignition timing is correctly set. Increase engine speed to about 4500 RPM. See IGNITION TIMING ADVANCE table.
| Application | Specification |
|---|---|
| V6 | (1) 27-33 @ 4500 |
| (1) Vehicle not in BASIC ADJUSTMENT mode, engine oil temp. at 176°F (80°C), and Blue engine coolant temp. sensor connected. | |
| (1) | Vehicle not in BASIC ADJUSTMENT mode, engine oil temp. at 176°F (80°C), and Blue engine coolant temp. sensor connected. |
IGNITION TIMING ADVANCE (Degrees BTDC @ RPM)
IDLE SPEED & MIXTURE
Note. Idle mixture is computer controlled and is not adjustable.
Note. Ensure fuel system pressure is correct before attempting idle speed adjustment.
MASS AIRFLOW (MAF) SENSOR
Information not available at time of publication.
DASHPOT
Open and close throttle until dashpot piston contacts roller. With throttle in this position, check gap between limiter (stop) screw and throttle. Gap between limiter (stop) screw and throttle lever must be 0.10-0.14" (2.5-3.5 mm).