2.3L ('83-'97) Air intake hose question

[Pavix]

I recently picked up a 97 2.3L manual ranger to drive while I rebuild the engine in my Terrain and while I'm going through and trying to sort out some issues, like why I'm only getting 15mpg or why I sometimes slow to 60mph on small hills or why 4th gear is completely useless, and it looks like my intake hose is covered in electrical tape. Does anyone have a part number for that hose as i'd like to get a replacement one if possible.

 

[RonD]

Welcome to TRS

Pretty sure wrecking yards will be the only place to find a replacement, which is why there is tape sealing any cracks in that tube
You can get 3rd party air plenums like this: https://www.amazon.com/Performance-Intake-Ranger-Mazda-Engine/dp/B07DQCP5HV

Yes, air leaks could cause lower MPG and lower power because engine is running too Rich, but you would usually get Lean codes if that was the case
Old O2 sensor would cause lower MPG and wouldn't set any code until it was way out of range
O2s use a chemical to detect oxygen in exhaust, they simply run out of the chemical after 100k miles or 12years, which causes them to tell computer to add extra fuel, so MPG slowly goes down and down over time

Pull out a couple of spark plugs and see what the tips tell you, i.e. running too Rich or not

In your picture, to the right of center and below the throttle cable, under upper intake is a silver "can" with a vacuum hose attached, that's the fuel pressure regulator(FPR)
Pull off that vacuum hose and see if it has gasoline inside it
If FPR starts to leak a bit fuel can get sucked into engine causing low power and low MPG, but would expect Rich Codes for that, but easy to check

In the 2.3l SOHC Lima engine it could also be timing belt is older and stretched a bit, so compression is down
Lower compression reduces power and so MPG also suffers
With spark plug out test compression, expected is above 150psi, closer to 165psi, as it runs 9.3:1 compression ratio

These 3 things are about the only things that can cause low MPG and power from the engine without setting codes
Old O2 sensor
Low compression
Exhaust manifold leak, sucks IN air, causing false lean voltage on O2

 

[Pavix]

For the FPR is this it?

This thing is a basket case, the previous owner did something to the dash and changed the back lights to blue instead of green but they flicker and only part of the instrument cluster lights up/flickers. I also believe he removed all diagnostic lights because when starting the truck the only light on is the airbag light which operates normally and goes out after a second or 2. He changed the factory 14 inch rims to 15's which does give the truck an aggressive look but I think is also responsible for my poor acceleration, the speedo being off, and probably a tiny bit responsible for the craptacular MPG. He replaced 2 plug and plug wires, I replaced 4 more which leaves the 2 on the drivers side closest to the firewall. That IAC looks brand new, but the cable for the cruise control doesn't catch on the rubber thing its by so the cruise doesn't work. And it's loud, I assume because the O2 sensor was causing issues and he removed it, but that's a guess. He could have removed the cat and done straight pipes back. And i have a new fuel filter and fuel pump/sending unit. The filter in hopes that I can salvage some MPGs with a new one, and the pump/sending unit because the fuel gauge shows full all the time.