ENGINE MECHANICAL
Before performing any on-vehicle adjustments to fuel or ignition system, ensure engine mechanical condition is okay.
VALVE CLEARANCE
Note. All models use hydraulic lifters. No adjustments are required.
9000 Series
Note. 9000 Series are equipped with Direct (Distributorless) Ignition System (DIS). Timing is not adjustable.
900 Series
Connect tachometer and timing light. Disconnect and plug vacuum advance hose (if equipped). Place transmission in Neutral. With engine at normal operating temperature, check ignition timing at specified RPM. See IGNITION TIMING table. Adjust ignition timing, if necessary, by loosening distributor hold-down bolt and turning distributor.
| Application | Man. Trans. | Auto. Trans. | |
|---|---|---|---|
| 900 Series | |||
| Non-Turbo | 14 @ 850 | 14 @ 850 | |
| Turbo | 16 @ 850 | 16 @ 850 | |
IGNITION TIMING (DEGREES BTDC @ RPM)
IDLE SPEED
- Ensure engine is at normal operating temperature. Ensure CO and ignition timing are correct. Locate dashpot and Automatic Idle Control (AIC) valve on throttle body. Loosen lock nut on throttle dashpot, and lower dashpot to clear throttle lever. Pull back rubber boot on AIC connector, and connect digital dwell meter leads to pin No. 3 and ground. Connect a tachometer. NOTE: DO NOT make idle setting when radiator fan is operating.
- Unplug throttle position sensor connector, and connect a jumper lead across pins No. 1 and 2 on harness side of connector. Check throttle position sensor and throttle cable for interference with movement of butterfly.
- Start engine. Ensure all accessories are off. On models without air bleed adjusting screw, loosen throttle stop screw lock nut. Turn adjusting screw counterclockwise until screw does not touch throttle linkage.
- On models with air bleed adjusting screw, loosen throttle stop screw lock nut. Adjust throttle butterfly-to-housing clearance to .002" (.05 mm). Loosen air bleed screw lock nut, and turn air bleed screw clockwise until it is fully seated.
- On all models, dwell meter should indicate about 34 degrees (4-cylinder scale) . If dwell is not to specification, check for vacuum leaks. Turn adjusting screw/air bleed screw until engine idle speed is 850 RPM.
- Dwell meter should indicate 32-35 degrees. Tighten lock nut on adjusting screw/air bleed screw. Turn engine off, and restore connections. Adjust throttle dashpot. See «DASHPOT ADJUSTMENT»(ref-15383-S26054843262001010800000) .
IDLE MIXTURE
Note. Mixture adjustment is not a part of normal tune-up procedure and should not be performed unless mixture control unit is replaced or vehicle fails emissions testing.
Start engine, and warm it to normal operating temperature. Using an exhaust analyzer, check CO level. If CO level is not within specification, turn CO adjusting screw clockwise to increase value or counterclockwise to decrease value. See IDLE SPEED & CO LEVEL table. Remove test equipment, and plug adjusting screw.
| Application | Idle RPM | (1) % CO Level | |
|---|---|---|---|
| 900 | |||
| Non-Turbo | 750-900 | 0.5-1.5 | |
| Turbo | 750-900 | 0.9-1.6 | |
| 9000 | |||
| Non-Turbo | 750-900 | 1.0-1.6 | |
| Turbo | 800-900 | 0.5-1.5 | |
| (1) General specification. Check local specification. | |||
| (1) | General specification. Check local specification. |
IDLE SPEED & CO LEVEL
PROGRAMMING ECU
Note. If power supply to ECU has been interrupted, system must be reprogrammed.
Drive vehicle for 10 minutes with engine at normal operating temperature.
Accelerate vehicle at full throttle at 2000-4500 RPM. Because programming occurs at 2750-4500 RPM and requires 3 seconds to complete, perform procedure in a gear permitting operation between those engine speeds.
THROTTLE POSITION SENSOR (TPS)
No adjustment is required. For testing procedure, refer to SYSTEM/COMPONENT TESTS article.