How to adjust the timing on a 1999 Ford F-250 Super Duty 4WD

You will need a hand held tuning device made by companies like SCT or Diablo-sport. Although why do you need to adjust your timing? Did you upgrade your exhaust and/or air intake system? This tuning device usually comes preloaded or can have custom tunes loaded based on your specific upgrades made to your vehicle by the tuning device vendor. The device plugs into a service port under the dash and your tuning mods can be made with the tuning device.

there is no timing adjustment its made by the computer