Throttle Body Injection
- Install timing light with an adapter between No. 1 spark plug and No. 1 spark plug wire, or use an inductive pick-up. Do not puncture wire. Disconnect 1-wire (Tan with Black stripe) timing by-pass connector at distributor.
- Place automatic transmission in Park and manual transmission in Neutral. Check and adjust ignition timing with engine at normal operating temperature. Reconnect by-pass connector. Clear trouble code by removing ECM power fuse for 10 seconds.
IGNITION TIMING SPECIFICATIONS (DEGREES BTDC @ RPM)
| Application | Man. Trans. | Auto. Trans | |
|---|---|---|---|
| Carbureted | |||
| 5.7L (Calif.) | 6 @ 700 | 6 @ 700 | |
| 5.7L (Federal) | 4 @ 800 | 4 @ 700 | |
| 7.4L | 4 @ 800 | 4 @ 700 | |
| TBI | |||
| 5.0L & 5.7L | TDC @ Idle | TDC @ Idle | |
| 7.4L | 4 @ Idle | 4 @ Idle | |