92 f150 4.9 running on 3 cylinders getting gas & spark I unplug 1st 3 plugs and nothing changes
You should change your plug wires.
Basics - Basics - Basics. Compression test, Vacuum leaks (especially the 4.9L with 70 pounds of manifolds hanging on side of the motor), Plugs and wires (as mentioned). A knowledgable technician with proper diagnostic skills would help too. You've posted this one before haven't you?
Search Ford F-150 Questions
Ford F-150 Experts
Related Models For Sale
Used Cars For Sale