need help 01 ranger edge 4.0

[brian1116]

i apologize if this has been covered already did a search and didn't find anything. I have an 01 ranger edge 4x4 4.0 4 speed auto I'm getting 8-9 mpg I filled up tank set my trip meter and refilled on empty to get this no check engine light and no codes I checked 4 times with 4 different odb2 scanners (marco, snapon, autozone special, and a cheapo brand). good spark from coil pack and plugs just did a full tune up oil, filter, air filter, fuel filter and plugs and wires runs good plenty of power and cleans maf sensor. But I can't figure this out any ideas? Oh stock height 245/75/r15 and a cherry bomb muffler are the only addons. I just bought thus truck a month ago it has 148k on it

 

[brian1116]

Could it be a possible o2 sensor issue? Or maybe someone who owned it before me used a power programmer on it and never changed it back to stock? Any suggestions?

 

[brian1116]

no help? ok well i replaced fuel pump 2 weekends ago filled it up took 17 gallons +\- and ive been driving it around ive put 100 miles on it and i have just above 1/4 of a tank. any thoughts? any help apreciated maybe a bad fuel injector there has been no trouble codes at all as of yet no saved codes no check engine light what am i missing? there is no vacuum leaks i used starting fluid and sprayed the back of the engine where the troubled vac leak usually is nothing i sprayed it all around the intake around the throttle body no change in rpms

 

[Earl43P]

Many scanners will show live sensor data.

Look at long term and short term fuel trims for a clue.

If it were mine, I'd go ahead and replace both upstream O2 sensors, since the PCM will adapt to lazy ones and won't throw a code. Since you don't know the history of the truck's maintenance, you should assume those O2's are original.

The other sensors that have a large effect on fuel trims are the Intake Air temp sensor, which is built into your MAF (can view that on many scanners too), Coolant temp and throttle position. You can test the CTS and TPS with a multimeter.

http://www.fordfuelinjection.com/?p=28
http://www.fordfuelinjection.com/?p=30
http://www.fordfuelinjection.com/?p=31

http://www.fordfuelinjection.com/?p=64

 

[brian1116]

Thanks earl I will check the tps and cts today and go buy some new o2 sensors should I just replace all 3 or just the front 2?

 

[Big Jim M]

Howdy Brian

Thanks earl I will check the tps and cts today and go buy some new o2 sensors should I just replace all 3 or just the front 2?

You didn't say where you are.. Also if it takes two weeks to burn 3/4 tank of fuel you should expect 10mpg! Good fuel milage occurs when the tank is emptied in just a few days or a few hours makes even better mpg. Remember the shorter the trips are and the more stops and starts there are in a tank of fuel the worse the milage will be.
The best milage would be at 50/55 miles per hour and an all day drive on the freeway. From there things go downhill.
Big JIm

 

[brian1116]

I'm in northern nv. City driving and I meant 7 days (1 week) not 2. 100 miles on the trip meter since I filled up and 1/4 of a tank left regular driving not getting on the pedal it takes 7 min for me to get to work and home I don't have any lights to stop for so its a straight shot

 

[Big Jim M]

Yep!

I'm in northern nv. City driving and I meant 7 days (1 week) not 2. 100 miles on the trip meter since I filled up and 1/4 of a tank left regular driving not getting on the pedal it takes 7 min for me to get to work and home I don't have any lights to stop for so its a straight shot

Seven minute drives are hell ain't they? I wouldn't expect much more out of a seven minute drive with hours between them.
Big JIm

 

[brian1116]

So you're saying its normal fuel consumption that I'm getting?

 

[Big Jim M]

Nope!

So you're saying its normal fuel consumption that I'm getting?

What I'm saying is to take it for a Sunday drive down the freeway at about 55 mph and see what you get with a straight on 100 mile drive.. ONLY then will you know what milage you are really getting.
Seven minute drives don't tell you anything.

Big JIm

 

[brian1116]

OK I gotcha I will do that tomorrow and get back to you

 

[bartkowski]

hi brian,
I am having the same trouble you are with the fuel mileage and i have done everything you have exept that i already replaced both my upstream O2 sensors and not just cleaned the MAF but replaced it also. I have made long trips in my truck but there is no difference in fuel economy on my truck. But what i did find was that if i disconnected my battery for 15min i would get 16-18 mpg for about a quarter tank before it reverts back to 8-10mpg.

If you have a multimeter you can test your O2 sensors to se if they are working correctly before you just replace them. I didn't know i could and would have prefered to save the money than replace something that was working correctly.

But like you i am having trouble getting answers on what the problem really is and not to many people have any suggestions. But one i did get was to check the "octane shorting bar" which if it was removed would retard your engine and it would run rich, it is located on the driverside by the firewall i havent looked for mine yet as i just got the suggestion and its rain out here. but ill see if i can copy and past the little pick of it. its just a two wire jumper basically that goes apperantly nowhere.

the loose one sitting there is an extra, the installed one is on the lower right of the pic, this is a 5.0L engine but it is what was sent to me to locate it.

 

[Big Jim M]

Please explain!

hi brian,
I am having the same trouble you are with the fuel mileage and i have done everything you have exept that i already replaced both my upstream O2 sensors and not just cleaned the MAF but replaced it also. I have made long trips in my truck but there is no difference in fuel economy on my truck. But what i did find was that if i disconnected my battery for 15min i would get 16-18 mpg for about a quarter tank before it reverts back to 8-10mpg.

If you have a multimeter you can test your O2 sensors to se if they are working correctly before you just replace them. I didn't know i could and would have prefered to save the money than replace something that was working correctly.

But like you i am having trouble getting answers on what the problem really is and not to many people have any suggestions. But one i did get was to check the "octane shorting bar" which if it was removed would retard your engine and it would run rich, it is located on the driverside by the firewall i havent looked for mine yet as i just got the suggestion and its rain out here. but ill see if i can copy and past the little pick of it. its just a two wire jumper basically that goes apperantly nowhere.

the loose one sitting there is an extra, the installed one is on the lower right of the pic, this is a 5.0L engine but it is what was sent to me to locate it.

"i would get 16-18 mpg for about a quarter tank before it reverts back to 8-10mpg."
Please tell us how the hell you found this out! I'd like to do it also..
Big JIm

 

[bartkowski]

i used the odometer mileage and how many gallons of fuel i used. i found before i reset the computer i would get 45-50 miles from full to 3/4 tank consistantly. then i reset the computer and done the same thing and i would get anywher from 85-90 miles from full to 3/4 tank.
also before reseting at about half a tank i was around 90-100 miles depending on my driving habits and again after reseting i was at 135-145 miles. so i assumed it took about a quarter tank for my trucks computer to learn the bad fuel curve.
Big Jim M please correct me if i'm wrong! i want answers just like brian1116, but this is his post and i don't want to hijack it but anything you have to suggest could possibly help him as well.
when i first bought my truck a few years back i could consistantly get 16-18mpg all the time and recently it has changed and it made a big difference on my wallet i went from filling my tank once a month to every two weeks. My truck before this was a '96 4.0L 4x4 supercab ranger but a standard and unless i was feeling froggy i was over 18mpg, i drove to north carolina once and averaged 20.3mpg but that is a flat drive too.

 

[99RangerOffRoad]

Also a fuel leak will give you bad gas mileage. I would check all the hoses. I have seen cracked filler hoses before and replaced one. The gas would splash out every time you turned. Those buggers can be expensive though.

Just one thing to check before you start throwing money at it.