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Web Wheeler
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Discussion Starter #1
So for about the past year or so I have been getting around 11mpg. I have no idea why, but it just sucks like none other. I get about 130 miles to a tank which works out to 11mpg. I have already replaced my inline gas filter, spark plug, cap and rotor, air filter, TPS, CPS, and 02 sensor. I don't get it because I don't drive with a lead foot, and the motor runs just fine.
 

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So for about the past year or so I have been getting around 11mpg. I have no idea why, but it just sucks like none other. I get about 130 miles to a tank which works out to 11mpg. I have already replaced my inline gas filter, spark plug, cap and rotor, air filter, TPS, CPS, and 02 sensor. I don't get it because I don't drive with a lead foot, and the motor runs just fine.
I was getting about that mileage for the past few months and could not figure it out so i started messing with random things and found out my front wheels were not spining right...i have a posi locker to lock in the front for 4wheel drive and that wasnt disengage so i got it to disengage and now the front wheeles spin free and im getting around 20 again...just i thought to throw out there for u
 

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Web Wheeler
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Discussion Starter #3
Hmm, I'll have to check that out. Any one else have any suggestions?
 

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I was getting mid 10's after the lift (when I started paying attention to it). I started driving really easy, rose to 11ish.

Cap, rotor, plugs, plug wires
O2 sensors
4:56 gears
TPS
Intake temp sensor
coolant temp sensor
cleaned throttle body
replaced cracked exhaust manifold
replaced catalytic converter and muffler

I bought a OBD II scanner. I have recorded data while sitting in the driveway and driving. My upstream O2 sensor is showing that the air fuel mixture is rich, at least that is what I am told.

Based on this my next change will be injectors.

I've been tracking my gas mileage since July of 2008. If I drive easy I can get low 13 mpg, which is about 230 miles per tank. (230 miles divided 18 gallons 12.7777 mpg) So I've seen a 2.5 mile per gallon change since I started this? Of course I haven't been running the AC which will improve the gas mileage. Summer time may see me going back to low 12's.

If you are getting 130 miles to a tank, that is 7.2 miles to a gallon!
 

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Web Wheeler
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Discussion Starter #5
I might just have to buy one of those scanners :)

I think the float is messed up because when the needle is on E it takes about 14 gallons to fill it up to the top. But I get about 130 miles out of a tank that takes about 12 gallons to fill up. I'm not sure how big my tank is so i just fill it up when it reads empty.

Do you know how I can read the fuel pressure?
 

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I might just have to buy one of those scanners :)

I think the float is messed up because when the needle is on E it takes about 14 gallons to fill it up to the top. But I get about 130 miles out of a tank that takes about 12 gallons to fill up. I'm not sure how big my tank is so i just fill it up when it reads empty.

Do you know how I can read the fuel pressure?
Yeah I'm just assuming you have a 20 gallon tank like me. If you have over sized tires, did you correct the speedo?

From what I have seen it is pretty easy. You just need the fuel pressure gauge. I decided I'd gamble $158 on rebuilt 4 port injectors instead $40 on a fuel pressure gauge. :thumbsup:

You know replacing the injectors isn't going to hurt anything and with 140k miles it's going to help a little at least.
 

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Web Wheeler
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Discussion Starter #7
Where can I get injectors? While I am at it, should I get some larger ones for more HP?
 

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I dont know if anybody mentioned it yet as I didnt read all of the posts :D But be sure your tire pressure is where it should be for on road conditions. I finally remembered to check my PSI and they were all way off, now im getting 2 mpg better then before.
 

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Do you carry any gear on a daily basis? Any additional weight will reduce MPG's. Skids, lifts, bumpers, armor all add up.

How are your O2 sensors? It's possible that the replacement you bought may have been bad or damaged between when it was made and you bought it. If they've gone bad you can lose a significant amount of mileage.
 
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