Lost 100 Miles per gas tank

[Peter Kampos]

Hi there,



It seemed to happen over night!!! I severly lost MPG...approx 100 miles per gas tank. The engine light is not on. Any ideas??? I have an 02 4x4 trac with 140,000 miles. 4.1 non-slip differential. My trac seems to idle well, but i've noticed that she is decellerating faster than usual.



This is what i've done to far.



1) Oil change with Mobil 1

2) changed out one caliper

3) new shoes and pads, machined both drums

4) cleaned my K&N air filter

5) 5 treatments of fuel injector cleaner. Anyone know of the best fuel injector cleaner???

6) new spark plugs and wires at 100 K

7) started using 94 octane gasoline as there is less ethanol in it..winter gas sucks!!!:wacko:

8) throttle body cleaner

9) checked and adjusted the psi in the tires

10) both front hubs/bearings are new

11) new sway bar links and tie rods...alignment is perfect

12) driving habbits are the same



Things i have not done.

1) looked into the O2 sensor and coolant temp sensor...but engine light in not on!

2) differential fluid, crankcase fluid...transmission fluid was changed at 100k



I hate it when things don't run perfectly...and I've been attacking this issue with everything I got. I have learned soo much from this forum..and Todd you are the man for starting this.



Any help would be appreciated guys. I hope i am over-looking something easy.



Regards,



Kamps

 

[Todd Z]

7) started using 94 octane gasoline as there is less ethanol in it..winter gas sucks!!!

Do you have an XCAL and programed the truck for the 94?? if not there is part of the problem...



Thanks, I like to be the reason people mod their truck..



Todd Z

 

[Rick Thompson]

fuel injector cleaners over the counter suck.



Try this out and it is cheap. check at the local car parts dealer and find a product called Sea-foam. it is billed as the miracle add it to everything and it does it all. guess what it works!!!!

run your tank down to about a half and then add one can of this stuff. run the engine for about ten minutes to ensure that it gets to the injectors and let it sit for about 2-4 hours, then ride around town normally to warm up engine. drive back home and then 3-5 times with truck in neutral rev it up to about 4,500-5000 for a second. this will clean out any debris.



one possible problem you need to be aware of. if you have not been regularly adding cleaner the whole system my be dirty and the other cleaners may have freed up alot of this and just be clogging up other injectors as soon as one is free. In which case break out a grand and head to the dealer for a clean up. Sorry!

 

[Rodger Tellefson]

I second what Todd said. Get an SCT XCalibrator 2 or 3 with a tune for 87 octane and one for 94 octane; so you can tell the engine computer which one you are using w/o going to the dealer to have it adjusted. In addition you need to clean your Idle Air Control motor (see Todd's project), and put a good synthetic oil in, like Royal Purple, the engine / transmission / differential will help too.



Techron Fuel Injector Cleaner does work. I add it to a tank of gas every 3 mos.

 

[Mike M 4]

Reformulated gasoline, happens to me every winter.

 

[Tom Schindler]

mikem is correct. Winter gas is to blame. I get a hit on gas mileage every winter. Add the different gasoline, along with colder temperatures and that is your problem.





Tom

 

[Bob McDonald]

but i've noticed that she is decellerating faster than usual.

That comment makes me wonder if maybe your tranny is never shifting into OD.

 

[Torrie McPhail]

If you have 140k miles and still have the stock 02 sensors change them. this will have a big impact if they are on the way out.



Take care,

Mr. Torrie R. McPhail - (Owner)

http://www.FastPartsNetwork.com

http://www.UnleashedTuning.com

Ford/GM/Dodge/Chrysler/Jeep SCT Custom Calibrator

 

[Rodger Tellefson]

Where are all of the 02 sensore located? Thanks

 

[P M]

but i've noticed that she is decellerating faster than usual.

That makes me lean more to a drive train issue. Brake dragging, rear end gear fluid loss, wheel bearing, etc. After you drive a bit, feel each hub and see if one is unusually hot. Could also jack up one wheel at a time and make sure each wheel is spinning freely.

 

[Todd Z]

Rodger, There are 3 of them.....



1 on each side of the y-pipe before the Pre cats and 1 in between the back 2 cats...



You can change them from under the truck and through the wheel wells..



Todd Z

 

[Peter Kampos]

 

[Rodger Tellefson]

Thank You Todd.

 

[Tom Schindler]

Rodger,



I have the special socket used to remove them. If you need it, let me know.





Tom

 

[Rodger Tellefson]

Thanks Tom, but it would probably cost more to send it to me, and back again, than it would be to just go out and buy one. :unsure:

 

[mookie]

I was thinking what PRM wrote; brake drag.



So... spin those wheels!

 

[Chris Taylor]

1st thing I thought of was brake drag too because of the deacceleration issue... As Mookie said, easy to check.

 

[P M]

Any updates??