1990 ford ranger 2.3l

This was already like this when I bought my truck, its a 90 with the 2.3 motor. My truck didn't have ac when I bought it so idk if this has anything to do with it or if there's supposed to be a hose or a pipe connected there or what. One person told me I didn't need whatever went there since my...

Hey guys need some advice. I’ve been lossing power at around 3300 rpms pretty consistently. Happens most at highway speed but parked in neutral if I rev up past 3000 it does the same thing. It hits a wall and loses all power. Changed fuel filter been throwing in a bunch of fuel cleaners. Cleaned...