Carbureted Models
- Place transmission in "P" (auto. trans.) or Neutral (man. trans.). Turn air conditioner and heater off. Disconnect and plug vacuum lines at distributor. Connect timing light and tachometer to engine.
- On 5.8L, disconnect 2-wire connector from ignition module and install a jumper wire between the 2 pins (Yellow and Black wires).
- On all models, start engine and warm to normal operating temperature. With engine at timing RPM, adjust initial ignition timing. Remove jumper wire. Reconnect all connectors and vacuum hoses. Remove all test equipment.
IGNITION TIMING SPECIFICATIONS
| Application |
Degrees BTDC @ RPM |
| 5.0L CFI (EEC-IV) |
10 @ 550 |
| 5.0L 4-Bbl. |
| Calif. |
10 @ 800 |
| Fed. |
12 @ 800 |
| 5.8L 2-Bbl. |
14 @ 600 |