New, to me, Ranger 4.0 bad MPG

Detectorist · #1 09-19-2011, 05:04 AM

Just purchased a 1994 4.0L Supercab 2WD. Engine sounds OK. May have up to 200,000 miles on it.

Fuel economy is terrible. Drove it home and got like 11 MPG. Need help on what to look for on this model besides the normal stuff like:

Air filter
fuel filter
plugs
wires

Any help would be appreciated or point me to another post with more information.

01B3000 · #2 09-19-2011, 07:01 AM

Ok well don't expect more than 15-16 mpg. Maybe run some injector cleaner through the tank, and how are you calculating your mpg? You said you drove it home and got that, how far was home?
Things to try,
The injector cleaner, check tire pressures, check that there the right tire sizes. Make sure you cel isn't burnt out, and the truck isn't giving you a code

Detectorist · #3 09-19-2011, 12:35 PM

It does have a check engine light. Don't know how to get the codes since Auto Zone's reader only goes back to 1996.

What is a 'cel'?

HazardousRanger · #4 09-19-2011, 12:38 PM

cel= check engine light lol

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make sure ur calculating ur mpg correctly. most people get this wrong!

fill up, reset trip odometer, drive, fill up, divide miles on trip odometer by how many gallons you just put in

ofc this doesnt work if you have bigger than stock tires in which case you need to read this:

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http://www.fordrangerforum.com/wheel...ck-tiires.html

Detectorist · #5 09-19-2011, 06:54 PM

Ok, calculated my latest trip. 75/6.2 gal = 12 mpg.

That was before this afternoon when I changed plugs, wires, air filter, fuel filter. Plugs looked good. Air filter was somewhat dirty, wires looked good, but went ahead and changed them anyway. Lots of gunk in old fuel filter.

Couldn't get to the MAF sensor because the screws securing it were 'screwy'. Torx with a pin in the middle, like they have in restrooms.

Keeping my gingers crossed.

Any suggestions on a fuel injector cleaner additive that actually works?

HazardousRanger · #6 09-19-2011, 07:02 PM

no idea, give it liek 300 miles or so before you get an official mpg. idk why but sometimes it takes awhile for it to get working again. ofc u can still calculate it after a few miles

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lots of people here use seafoam...but ur supposed to change ur plugs afteer you use it... lol

01B3000 · #7 09-20-2011, 04:18 AM

Actually sea foam on an engine that old is no good, maybe if the owner ran sea foam maybe once every 50,000 miles id say go for it, but its first time at 200,000 miles, it could cause problems, or so i heard. What i like to use is the cheveron techron stuff, or whatever its called.

That check engine light could be the reason for your bad mileage also, id get it checked elsewere, your going to need an OBD-1 scanner, i dont know who has them anymore since they are basically everywhere, might be able to get a good deal on one online.

changetodanger · #8 09-20-2011, 04:29 AM

Quote:

Originally Posted by Detectorist

Just purchased a 1994 4.0L Supercab 2WD. Engine sounds OK. May have up to 200,000 miles on it.

Fuel economy is terrible. Drove it home and got like 11 MPG. Need help on what to look for on this model besides the normal stuff like:

Air filter
fuel filter
plugs
wires

Any help would be appreciated or point me to another post with more information.

Maybe check the vacume hoses around the throttle body, and intake manifold. check airfilter for oil. it may have bad rings causing it to have lower compression meaning that the motor has to work harder to keep up and pushes more fuel through. might even check o2 sensers. or injectors

Badmotorfinger1 · #9 09-20-2011, 10:18 AM

You definitely need to pull the CEL code. Check around the auto parts places for an OBD I code reader. O'Reilly's has them I believe. They're pretty cheap.

I'd also think about replacing the O2 sensors. A bad sensor can kill MPG.

IIRC, you don't need the special socket to clean the MAF. Pull it out as an assembly and spray MAF cleaner into the cylinder. Be very careful not to touch the wire running though the body. I believe there is a "How To" on cleaning the MAF if you do a quick search.

Pour in two bottles of Chevron's Techron next time you fill the tank. It's the best cleaner on the market.

Detectorist · #10 09-20-2011, 03:03 PM

Ok. I really appreciate the advice. I've got the CRC MAF cleaner. I figured I could also use it to clean other electronics since I didn't have an electrical contact cleaner. I'll clean the sensor tomorrow. The cleaner did come with a nice long straw thing.

The truck seems to have a bit more power now. I did discover on the Internet that Ford has a Technical Bulletin on the sensor. It basically says that they go bad and to replace them. lol

redman7 · #11 09-20-2011, 03:16 PM

check your engine temperture if the thermostat it is stuck open like mine was the engine does not get up to temperature my MPG went from 12-13 to 19-20 after I replaced it. Also reset you milage gage fill up then drive to about 1/4 tank then fill it at the same gas station pump then divide miles driven since laSt fill up by gallons of gas pumped

Detectorist · #12 09-20-2011, 04:09 PM

Quote:

Originally Posted by redman7

check your engine temperture if the thermostat it is stuck open like mine was the engine does not get up to temperature my MPG went from 12-13 to 19-20 after I replaced it. Also reset you milage gage fill up then drive to about 1/4 tank then fill it at the same gas station pump then divide miles driven since laSt fill up by gallons of gas pumped

Funny you should mention that. Even though I get good heat from the vents, the Temp gage won't go above 1/8" over *cold*. I'm used to temp needles going at least 1/4 of the way up. In any case. I've got a new thermostat I'm putting in. As soon as I figure how to get to it. I might have to take the belt off.

redman7 · #13 09-20-2011, 07:42 PM

It's not that hard can't remember if I had to take of the belt but it is located on the front of the engine there is a pipe that looks like a letter J I took the time to paint this part when I took it off because it was rusting and for some reason I know it cost like close to 100 to replace. But it took me like an hour to do it all glad I was able to help hope it solves your mpg problems also proper tire inflation and keeping the rpm's around 2000 will make a big difference and not using the AC

02RangerFX4 · #14 09-20-2011, 08:24 PM

Dang man, 11? On a good day I get like 19-20

Chargerondavins · #15 09-20-2011, 08:34 PM

I have had 3 4.0 liter fords...

The 2wd ranger I got about 16mpg, my 1995 4.0 4x4 got about 15mpg, and my 2003 4.0 gets about 14mpg.

I take it pretty easy on them too.

The good news is, the 3.0 is only 1mpg or two MAX better mileage and much slower. I currently own a 3.0 ranger and a 4.0 explorer. Love them both, but it is what it is.

The high mileage issue with sea foam - i don't buy it. Bought/sold cars for years, sea foamed over 30 myself with 200k+, did nothing but help them. Run a can in the gas, a little in oil (then change oil after 50 miles or so) and then run some through the throttle body till it chokes out and stalls. Start it off slow so it sucks it in, gradually pour faster till it dies. Wait 10 minutes. Fire her up. She won't want to start for the first 2-5 seconds, and will run rough at first, then will cough up ungodly amounts of carbon and other crap (most of which though is just the sea foam, but you have HELPED your car).

Also, fuel filter should be replaced. Fords need those replaced every 30k, or else you really risk your fuel pump.

Above advice is pretty solid, IME