1985 Honda Civic High idle, massive fuel consumption runnin

Engine Performance problem
1985 Honda Civic 4 cyl Two Wheel Drive Manual 180k miles

Hello, we just got a 1985 Honda Civic. I was driving it a little while ago and noticed that the throttle wasnt really responding right, reved up no problem but stayed up and when it did come down my guess is it was somewhere in the 2000 RPM range (no tach). It stayed in that range burned through 3+ gallons of fuel in a one mile span. I'm not sure if there was any fuel smell as my nose is just loving all the allergens in the air. Was running really rough, almost sputtering which got worse the more I tried to accelerate, thinking I was almost out of fuel maybe being the cause of that? I thought maybe vacuum leak? Of course the way I was watching the fuel gauge go down I also thought there was a hole in the gas tank. Also likely unrelated but who knows, theres a strange water or steam surging noise behind the dash board?