Gas Milage Problem

[Asugolf14]

I am having a problem with my Explorers gas milage. I got my explorer almost a year ago, and I was getting around 18 miles to the gallon, and I am now down to 12. Is there anything that would cause this? Anything I can do to increase?? Thanks

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Asugolf14
'93 Explorer slightly modified

 

[JoeC5]

You can do a search on this topic, but most of the time bad gas mileage is due to a bad fuel pressure regulator. But before that start off with when was your last tune up(spark plugs, plug wires, clean maf and so on).

 

[Asugolf14]

Yeah, I did a search on it, but I didn't notice that anybody was decreasing in gas milage, they were looking for a way to increase gas milage from their norm. Thanks for the info though.

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Asugolf14
'93 Explorer slightly modified

 

[Chav]

I would lay blame on the 02 sensors. It usually takes much more then 100K before the Fuel Pres. Reg. decides to quit. You can check the vacum line that comes off the fuel pres. reg. and see if there is gas in there. A better way to check your Pres. Reg. is to put a fuel pres. gauge on the shrader valve on the fuel rail. It should be around 38 psi at idle. Even if the check engine light isnt on a dirty 02 sensor can destroy your gas mileage.

-Chav

 

[DOGMAN]

Another possiblity is an open thermostat. If the motor doesn't get up to the correct temperature, it will run very rich, thus reducing mileage. Do you have a problem with the temp guage not coming up to temp normally?

You don't say whether the motor appears to be running smoothly or not. It definitely could be a sensor. It would be a good idea to run a diagnostic check and see if that turns anything up.

 

[PandaPimp]

I recently encoutered this problem myself. It turned out to be an O2 sensor behind my catalytic converter, some kind of mass regulator (i can't recall) and dirty fuel injectors. After all this stuff was changed/ cleaned my gas milage went back up to 19. I do have a 97, so I am not sure if it is the same as yours.

 

[Asugolf14]

Thanks for all of the info. I think my only problem is that the spark plugs and wires are shot. Lately, right after starting my car, it will start shaking a little, so I think that is my problem. I am going to take it in for a tune up in a couple days. If that doesn't fix anything, I'll let you guys know. Thanks

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Asugolf14
'93 Explorer slightly modified

 

[B94Sport]

I had a similar problem with mileage. I went from 18 mpg highway to 10 mpg. I got home, changed my O2 sensors, fuel pressure regulator and throttle position sensor, and now I'm back up at 18 mpg highway - and that's with these oxygenated fuels. I could probably get close to 20 highway when the weather warms up. No more check engine light either, which constantly plagued my road trips.

 

[Asugolf14]

ummm....guys...

Well, I just had a tune up done-new spark plugs, spark wires, air filter, and fuel filter. And, I hate to say it, but it hasn't done anything to my gas mileage. So do you guys think it is probably in my O2 sensors? If you do, what can I do to fix that? Do I have to pay a place to fix it for me, or can I do it by myself?? Thanks-

 

[DarkFox1]

how often would an O2 sensor go bad? I have a '97 and in the past few weeks I've been hardly able to pull 200 miles a tank, I used to be able to do almost 300, its been very sluggish latley too, hafta push the pedal waay down to make it even slightly pull, this sluggishness makes it hard to drive in tight traffic. whattyall think? I just dual exhaust installed, and for the first few days it performed great, but recently its not been so hot.. perhaps the weather has an effect?

 

[Tourture]

i would look at the O2 sensors as well.....i have the same problem with my 93 XLT....i've done plugs, wires, air filter, new fuel filter, checked the fuel pressure regulator.....nothing has worked so far.
as time permits, i will change the O2 sensors, hopefully that'll help.