your fuel pressure seems pretty normal.....try swapping out your mass air with someones that you know works. i had a 90lx that would buck and run like shi* when it was moist or raining out, and when it wasnt raining out it would not like full throttle, it would run better at half throttle.
if you know someone else with a mustang just swap sensors, its free
from your pics it looks like you have a small crack in the cap, that could be letting moisture in also, try that too