2.3 5 speed getting horrible mileage

[Notch]

I just picked up a '92 Ranger. It's a RWD Northland edition longbox, rwd, 2.3, 5 speed. I picked it up hoping to use it as a beater until I'm done with school for the year, as I drive 160 miles round trip to and from school every day.

Well, I have been following my mileage, and it seems that I'm getting about 18 or less MPG in the city, and only 20.5 or so MPG on the highway. This is without me letting it idle to warm up, running out gears eccesively, etc. Being that my Mustang was formerly a 2.3 car, I've noticed that the truck also feels really doggy going up hills and accelerating, even for a 2.3.

There is no CEL on. From what I've read, common problems that should be looked into are a plugged cat or a locked up fan clutch. I'm not sure how one would check a thermal engaged fan clutch to see if it's stuck or not, but I've been thinking about pulling the fan off and driving down to school and back for a day without it (the weather has been anywhere from -20 to 20 degrees around here lately) to see if it would make a difference. I'm kind of leaning towards a cat though, due to the the truck's mileage of x36,000, which I can only assume that that X is a 2.

Also, it doesn't seem to idle rough or run rough at all. Just seems down on power and mileage.

Anyways, thanks for the help. I just want to get some decent mileage out of my little $400 shitbox

 

[FGorhau]

I always look for the cheap stuff first... I'd check the O2 sensor... I had one once that wasn't bad enough to light the CEL, but was bad enough to screw with my mileage.

 

[Notch]

Maybe I'll grab a couple next time I'm at the junkyard. Like I said, it is a $400 beater that I need to last a couple months, so I don't want to throw much money at it at all.

 

[Notch]

Well I put just plugs in it last night and drove it to and from school, and picked up maybe half a MPG if anything. The old plugs looked like shit though, so I was hoping that would help.

I'm just wondering, but does the instrument cluster use the same coolant temp sensor as the computer does to read the coolant temp? My coolant gauge isn't working, and I've heard that a temp sensor is pretty common, but if it uses the same sensor as the computer uses, than I'd think maybe the truck isn't going out of closed loop.

Thanks for any help!

 

[fastpakr]

Is the CEL definitely working, i.e. is it lighting up briefly when you turn the key on? If not, troubleshoot that.

I'd run the diagnostic tests regardless of the CEL. Assuming the CEL is functional, all you need is a paperclip.

Also check fuel pressure, check for vacuum leaks, and if you're concerned about the O2's, you can backprobe those with a voltmeter.

 

[locovaca]

Well I put just plugs in it last night and drove it to and from school, and picked up maybe half a MPG if anything. The old plugs looked like shit though, so I was hoping that would help.

I'm just wondering, but does the instrument cluster use the same coolant temp sensor as the computer does to read the coolant temp? My coolant gauge isn't working, and I've heard that a temp sensor is pretty common, but if it uses the same sensor as the computer uses, than I'd think maybe the truck isn't going out of closed loop.

Thanks for any help!

No. The Gauge Sender (which go bad all the time, see the million of posts on here about it) is in the block under the intake, the computer sender is near the thermostat on the line going to the heater core. The computer one goes bad less frequently but is easier to replace. However, the chances of it going bad and still outputting some recognizable to the computer are slim. If you want to test it, boil some water, place the sensor in the water, and read the resistance, should be around 2.07k ohms at boiling (212).

 

[Notch]

Well, I think I got it nailed tonight. I used our fancy new scanner at work (work as a mechanic) and watched the 02 in realtime, and it was graphing a flat line instead of spiking the voltage like it was supposed to. I also noticed that the truck has been stuck in open loop since I got it due to the bad 02. I threw a new upstream 02 in and it went into closed loop right away as soon as the engine heated up a bit.

I'm going to see if the mileage went up at all on the next fill up and let you guys know.

And locovaca, I actually looked up all of the EEC and the gauge wiring diagrams for the truck at work after I posted last, but thanks for the help. I'm a Mustang guy and this is just my beater, so I'm still learning about all of the differences with these trucks.

 

[JibbaJibba56]

Locked Up Fan

My 00 had a locked up fan when I bought it. Trust me you will know via sound if the fan clutch is toasted. Your truck will sound like a Semi-tractor revving through gears in the city or a towmotor/forklift (fans are always on). Also, your truck will barely do 55 on flat ground...

You could wait for the truck to cool down after you shut it off, grab the fan, truck still OFF, and see if it freewheels, truck still OFF. If not, you're locked.

Good luck increasing the mileage. My 2.5 with 190K on it pretty much locked in at 19 no matter how you drove it.

 

[Notch]

Best I've gotten since I did the 02 swap has been 21 mpg on the highway. I'm going to keep chasing the problem, as I would hope this thing would get better mileage.

And on a side note, while I was driving today, the passenger side tranny crossmember mount rusted off of the chassis. So I had fun welding that back on. Poor little rusty truck.

 

[VlvtnRbt]

'91 5 speed mileage

Before I lost my Cambelt I averaged 26 mpg with a bad clutch fixed that, 26 mpg Changed to 60 series tires revs increased maybe by 350-500 rpm still got 26 mpg because I was able pull 5th gear more easily. 39 miles 1 way commute mixed 2 lane highway and interstate- 2100 rpm at 55 mph- I had to keep careful track becase my gas gauge has never worked so I have to use my odometer.

 

[mattpresley]

You gotta remember for the posts sake. The mustang with the 2.3 was I much lighter car therefore faster and a better hill climber. I think your miliage issue has a lot to do with your right foot!

 

[Joey Stacks]

Yeah with some intake and exhaust mods mine gets 23 in the summer and 19-18 in the winter for some reason... Crappy winterized fuels are prolly the culprit

 

[dmassey]

No. The Gauge Sender (which go bad all the time, see the million of posts on here about it) is in the block under the intake, the computer sender is near the thermostat on the line going to the heater core. The computer one goes bad less frequently but is easier to replace. However, the chances of it going bad and still outputting some recognizable to the computer are slim. If you want to test it, boil some water, place the sensor in the water, and read the resistance, should be around 2.07k ohms at boiling (212).

When my temp gauge stopped working I thought my temp sender on the block was going bad so I was going to check it but I noticed when I took off the wire that it wasn't fitting very tight so I cleaned the connections thinking there was probably some corrosion, put it back together and it's worked fine ever since. Just an idea. Don't have much to offere about the gas milage as I'm trying to figure out a drop on mine too. Getting ready to either clean or replace the injectors. Rock Auto has service kits for $33 ea. or complete injectors for a bit more plus $10 core charge. Not sure if someone has addressed the stopped up cat but if that's the case you should notice a dramatic decrease in exhause pressure when you hold your hand over the exhaust while some one presses your accelerator - keep in mind the pipe is hot.