Gas Mileage Dropping Like Enron Stock

[LudusHatesReese]

Over the past two weeks I've noticed that my gas mileage really sucks, i went from about 250 miles to a tank to about 200. What could possibly be wrong and can i fix it easily?

 

[mrboyle]

The frist plase to start is checking your air filter, fuel filter and even tire pressure. If it hasen't been changed in the last 70K miles I would suspect the O2 sensor.

 

[LudusHatesReese]

The o2 sensor is brand new, but i'll check out my filters. My tires are my babies, and i keep them in prime running condition . Thanks.

 

[ok89]

Hey Mike my vehicle has almost 79k miles on it. How do I check o2 sensors?

 

[Jason_25]

hey run a fuel pressure test for us and see what you get. You're FPR may have gone south.

 

[LiKuiD]

at least you get 200!! i dont even get that on a good day! i dont have any suggestions though sorry im still fighting this battle too.

 

[mosinman]

Sudden decrease in mileage: Fuel pressure regulator, plugs, wires, airfilter, O2 sensor, and sometimes MAF. I suspect one of the first three. Good luck.

 

[aldive]

Take a real good look at the oxygen sensors.

Good luck.....

 

[Crankcase]

Could you be using your air conditioning more?

 

[Anime]

brakes

If everything else like air filter, fuel filter, plugs, wires, etc check out, you might want to check the brakes.

Check the front calipers to be sure the slide pins are well greased (with caliper slide grease) and check the rears to be sure the parking brake cables arent rusted or seized, and the shoes arent being held apart (even slightly) with the parking brake off. If any of the brakes have really worn pads or shoes, its a pretty good indication its rubbing, especially if the others still have plenty of material on them.

 

[mosinman]

Checked my Hayne's manual. In addition to the above, dirty fuel injectors and thermostat stuck in the open position were also listed. Man, you gotta lotta stuff to check.

 

[Big E]

I would think if you had a brake issure you would already be smelling some kinda of burning and see smoke roll out the the vehicle after long drives.

I think I would look into the O2 sensor. If it were plugs and wires they would have given some kind of notice and usually have a misfire. But usually when a O2 sensor goes it just goes. Pull the plugs out see if they are black and sooty. If they are then I would say you have a bad O2 sensor or a bad coolant temp sensor.

Just a few things to look into. Keep us posted.

Eric

 

[LudusHatesReese]

Brakes are new, and my air conditioner is temporarily out of freon. I'm gonna spend this weekend changing out my filters and plugs and wires. If that doesn't work then i'm gonna let the guys at the shop look at it. I'll keep you posted

 

[Luv2explorer]

I had the same problem with my 92x. I changed the plugs and wires(gapped plugs at 52), cleaned the MAF, and the IAC, drilled the air filter box, REPLACED the fuel pressure regulater, fuel filter, retorqued the lower intake bolts, and ran some fuel system cleaner. And since the a/c didnt work, and I didnt feel like fixing it- I took out the A/C componants. That was about 2 months ago, and I went from about 220 miles a tank to around 300(depending on how nice I treat her). Let us know how it goes!!

 

[bubble874]

reply

Ok i have a 91 x with 6" lift 32's, and roof rack with lights on it. I get 400 miles to the tank. Heres what i do. I got a K&N filter. STP fuel injector cleaner. And the most important thing, use AMACO gas. This is the gas car companies use when conducting mileage tests. Also, don't drive the truck hard. Drive it nice and easy, that way you will burn less gas.

 

[LiKuiD]

400?!?!?! your insane!!! heres to 210 a tank!

 

[bubble874]

reply

Holy crap what, are you pulling like a tractor. Thats really low. My dad's V8 gets 250. Geeze.

 

[mosinman]

1999 sohc XLT 4.1 rear end. 250- 275 town, over 325 highway. NO intake or exhaust mods. **** retentive maintenance.

 

[Jason_25]

My truck has a lift and 32" tires and even with the spare on the roof I get near 21 MPG on extended trips.

 

[bubble874]

reply

It is the Amaco gas. You can feel and hear the difference when you use Amaco.