Throttle Body Injected Engines

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. Ensure "SERVICE ENGINE SOON" light is off.
Disconnect EST by-pass Tan/Black stripe wire connector. On 5.0L and 5.7L engines, this connector is located near distributor. On 7.4L engine, this connector is located behind electrical junction box cover or inboard of bulkhead wiring connector.
Check and adjust ignition timing with engine at normal operating temperature, transmission in Drive (auto. trans.) or Neutral (man. trans.) and A/C off (if equipped). See IGNITION TIMING SPECIFICATIONS table. Reconnect Tan/Black stripe wire connector. Clear ACM trouble codes. See appropriate article in COMPUTERIZED ENGINE CONTROLS section.

IGNITION TIMING SPECIFICATIONS (DEGREES BTDC @ RPM)