Ignition Timing
NOTE:
Magnetic probe timing device may be used if instrument is available and engine is so equipped. Timing probe offset is 135° ATDC on all V8 engines.
- Determine specified timing and mark degree line on damper (some vehicles mark both pointer and damper notch). Disconnect vacuum line(s) at distributor and plug.
- Connect tachometer. Connect timing light to No. 1 spark plug wire. If vehicle is equipped with barometric sensor, disconnect sensor from module. Connect Black and Yellow wires in module connector. Set timing to specifications if more than 2° variation is found.
- To adjust, loosen distributor hold-down bolt and rotate distributor to align marks in step 1). Tighten hold-down bolt and recheck timing.
TIMING SPECIFICATIONS (DEGREES BTDC @ RPM)
| Application | Man. Trans. | Auto. Trans. | |||
|---|---|---|---|---|---|
| 5.0L | |||||
| Calif. | (1) | (1) | |||
| High Altitude | 12 @ 800 | 12 @ 800 | |||
| All Other Models | 8 @ 800 | 8 @ 800 | |||
| 5.8L | |||||
| Calif. | (1) | (1) | |||
| Light Duty | 10 @ 800 | 14 @ 800 | |||
| Heavy Duty | 8 @ 800 | 8 @ 800 | |||
| 7.5L | |||||
| Calif. | 6 @ 800 | 6 @ 800 | |||
| All Other Models | 8 @ 800 | 8 @ 800 | |||
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