What is ignition timing for 1991 Crown Victoria with a 5.0?

You can't give a single, precise ignition timing number for a 1991 Crown Victoria 5.0L without more information and specialized tools. The ignition timing is computer-controlled and varies dynamically based on many factors including engine speed, load, temperature, and oxygen sensor readings. There's no fixed degree setting like in older, purely mechanical ignition systems.

To find the *current* ignition timing, you'd need a scan tool capable of reading live engine data, such as a professional OBD-II scanner. Even then, you might only see the calculated advance, not the actual timing at the distributor.

Trying to manually adjust the ignition timing on this car is strongly discouraged unless you're an experienced mechanic with specialized equipment. Incorrect timing can seriously damage the engine. If you suspect a timing issue, it's best to diagnose the problem with a scan tool and then address any underlying issues with the engine control system (sensors, computer, etc.).