14MPG? 2.7 single cab. I think somethings wrong

If you read my other posts u know my mileage went from 18 to 16 and now its hit 14mpg. idk what it is but any help would be appreciated. new MAf sensor, wires,engine temp sensor. i just dont know

 

I would check for a leak, if it's not running poorly, fuel is pouring somewhere, maybe on the ground ?

 

Have you kept your truck maintained at regular intervals? I changed new plugs and wires recently and it jumped 2MPG. It would be also smart to change over to synth fluids too.

 

No check engine light?

 

O2 sensor could be stuck in closed loop where its just dumping fuel in... no light would come on as long as it thinks the sensor is working

 

Don't you mean it is stuck in Open Loop (rich)? Closed Loop (leaner) is where it runs after it's warmed up. Open loop only happens when it's first started.

My ScanGauge runs in "CLSD LP" during normal operation.

To answer the original question: Yes, something isn't right. I have the same motor and I'm getting 26.1 mpg average for highway driving. I just did a 715 mile round trip (all highway) @ 70 mph with cruise control. Filled tank to brim visually both times I refueled. Total was 27 gallons, even. 715mi / 27gals = 26.1 mpg

If I set cruise to 65 mph I get 29.8 mpg average.

 

I see you have a K&N drop in. Perhaps a fouling of the MAF sensor from the oiled filter?

Try cleaning the MAF sensor?

 

yeah ha ha sorry closed it chesks itself.... open it just guesses everything is ok lol

 

i put the scantool on and it says insufficent engine temp for closed loop operation. i changed the engine temp sensor and it still says it. there is the one on the back of the block which i changed and there is one up front right on top of the coolant hose. i figured it was the one on the back because the other one is kinda small which makes me thing its for a light or something. It has a new MAF sensor and new plugs ,wires. it gets better mileage when its warmer so i dint know if that has something to do with tit

 

yeah thats the problem its not reading that the engine is warmed up so its keeping the truck in open loop and just dumping fuel in... I'd say try the other temp sensor or i know its a long shot but maybe the engine management computer? hate to think its that but possible

 

would that make it ilde rough? It does that too

 

this may have been asked before but... do you have your hubs locked in?

i left mine locked for just one day and got on the highway running about 75-80 i could notice the fuel gauge going down. even with them unlocked i still dont get that good of mileage on the highway unless you run 65.

 

they have been since we have been getting 2-3ft storms once a week. I turn them off when it clear though

 

yeah sounds like the 02 sensors or computer... cause they would cause it to dump in too much fuel causing rough idle

 

HEY GUYS IM NEW.....how do you lock and unlock hubs? i just wanna make sure mine arent locked. thanks

 

Locking hubs are on the front, both wheels, and will have a small handle/grip to turn the hubs in either the locked position or the unlocked position, unless your presently in deep snow or mud you should be in the unlocked position. If you live in a part of the country where you are in and out of 4wd some folks lock the hubs in basically for the winter, engaging the transfer case to engage the 4wd system, but with rising fuel cost I wouldn't.

 

Seeing that you have a pre-runner, your hubs are not locked as you do not have a front drive-line, so you don't need to worry about it. But Jedi's post above does cover the operation of the hubs if you were just looking for information for the sake of having it.

 

A long shot here but just a few things my friends old `86 w/22RE,5 manual,only got 16mpg w/31-10.5s..Winter blend fuel aint worth a stink..In winter we (except my wife) let our vehicles idle longer..A vehicles gonna work harder in the snow..just wanted to make a few comments maybe 16mpg aint that far off.Should not idle rough though, is the truck actually warming up? Stuck thermostat?