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Discussion Starter #1
My 97 F-350 Is Down To About 8mpg And Is A Guttless Wonder. Anything Over 1800 Rpm's It Just Falls On It's Face, No Power At All But Other Than That Runs Awesome. It Is Totally Stock Other Than Cold Air Intake. When First Purchased Truck I Was Around 12 Mpg But It Ran Great In All Rpm's. It Feels Like Either Someone Put A Cork In The Exhaust Or I Just Run Right Out Of Fuel, It Does Have A New Fuel Filter And Have Tried Many Additives. I Have Heard These Truck Get Any Where From 15-20mpg I Am Getting Really Frustrated Any Help Would Be Great. Also No Lights On The Dash At All. Thanks In Advance For Your Help.
 

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TDG MAFIA MEMBER #77
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How is your fuel pressure?
Is the EBPV stuck partialy shut?
How about oil? Is it full? Been changed lately?

Start with the simple stuff - oil, then move on to the fuel pressure. If you are low enough on oil, you will be weak on fuel pressure.

How to check fuel pressure.
Get a good liquid gauge that runs up to 100 pounds and attach it to 3 feet of fuel line (1/4" ID) and appropriate fittings. You will need 2 hose clamps. Remove the guts to the shreader (sp) valve on the side of the fuel filter and clamp the hose on. Place the gauge on the windshield where you can see it from the drivers seat and crank the motor. You should see a minimum of 45 pounds. Rev it up and see what happens. If the pressure drops, start looking for the cause. Could be a bad pump, bad filter, return line screen could be clogged up, etc.

Next idea
I have a friend that owns a diesel garage. He had a late 99 come in last summer with the same symptoms you have. He went through all of the obvious things to check and it was all OK.
He ended up taking out the fuel tank and found that it had about an inch of a black carbon / crystal build up in the bottom of the tank that was blocking off at least 85% fuel delivery to the pump. He cleaned it all out and the problem was solved.

Let us know where you get.
 

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Discussion Starter #3
Thank You So Much For Taking The Time To Explain A Few Things To Me. I Had A Oil Change Done Last Week. It Was Right Up Where It Should Be, But I Will Check Again Tonight. Then I Will Build The Fuel Pressure Gauge And See Where That Takes Me. I Did Also Check The Ebpv And Actually Disarmed It And Wired It Open To Make Sure It Did Not Close Going Down The Road. Thanks Again For Your Help I Will Let You Know What I Find. Do You Think My Exhaust Theory Is Probably Incorrect, Like A Plugged Cat?
 

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Maybe the cat is stopped up creating back pressure.
 

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TDG MAFIA MEMBER #77
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Ooops! I over looked that part of your questions...:damnit

If you don't have to do emission testing in your county, kill that cat! That could very well be the problem. If you do have testing, just gut it out and leave the empty cat in place.
 

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Discussion Starter #6
Nop No Testing Here In Michigan. I Think I Will Do The Fuel Pressure Test And Then Order A Full 4 Inch Exhaust System Anyways. I Have Heard That They Do Make Alot Of Differance Because Of The Very Restrictive Down Tube. Even If It Is Not The Cat Maybe I Can Pickup 1 Or 2 Mpg In The Mean Time.
 

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Discussion Starter #7
Well Thanks To You Guys I Think I Got Her Figured Out. I Built The Fuel Gauge And Showed About 52 Psi At Idle And It Built Prussure With Rpms. So I Then Turned My Direction To The Cat. I Cut It Out And That Sucker Was Packed Full Could Not See A Bit Of Light Thru It. The Truck Know Runs Like It Never Has Before. I Just Ordered A 4 Inch Turbo Back Exhaust System, And A 6 Position Ts Performance Module. Hopefully With That Cat Out Of There And The New Goodies I Can Reach 16-18mpg. Thanks To All Of Those That Assisted Me I Will Let You Know About The Mileage Report When I Have Some More Drive Time On It. Thnaks Again
 

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Hopefully that setup has a 3" DP or you will have to do some major modifing of the firewall to get the 4" in there. But i've seen it done!! LOL
 

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Enjoy your new ride, cause if your experience is anything like mine, the change to a 4" exhaust system is like making your truck new again. Now I have to fight with my wife over who gets to drive the truck. ( and if you're wonderin' - she wins) :bow:
 

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my 96 F350 gets about 22 mpg and the only thing i have done is a bigger compressor wheel. :shrug:
 

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Whitey96 said:
my 96 F350 gets about 22 mpg and the only thing i have done is a bigger compressor wheel. :shrug:
What wheel did you use? I need more air and can't afford a bigger turbo.
 

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the stock one still. but its 2wd
 
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