7.3 horrible fuel mileage

Powerstroker91 · Mar 30, 2015

Well my 2000 f250 mpg seems to be extremely low went from 14-15 hand calc to 10mpg... the truck is always maintained and i change all the fluids before there even supposed to be changed im really particular about my trucks, new ebp tube and sensor, new fuel filter, oil, diff fluids, tranny fluid, always run fuel additives, hooked up ae and nothing seems to be wrong at all... Why is my mileage soo bad all of a sudden?

Magnum PD · Mar 30, 2015

Fuel leak?

Powerstroker91 · Mar 31, 2015

From what im seeing no fuel leak, nothing at the fuel bowl, none of the lines look wet, brakes recently replaced had a hanging caliper (front and rear), im puzzled.... The biggest problem is that it runs perfect and i dont know where to start, im getting good fuel pressure around 70psi at the head.

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superpsd · Mar 31, 2015

Do you have a scanner to read I/Os from the pcm?

pullandpray · Mar 31, 2015

Did you just get chitty diesel? Letting it idle more than usual? I know mine drops pretty low in the cold months

Powerstroker91 · Apr 1, 2015

Yeah i got auto enginuity but im not seeing anything out of the ordinary. Diesel fuel seems good. No running issues, starts with ease in the coldest weather here in PA, idles fine, runs perfect, doesnt have a tick.

wildbill963258 · Apr 2, 2015

did you check to see if you have a fuel leak in your fuel tank (there especially prone to start leaking under the support bands where you cant see it unless you remove the band)

Powerstroker91 · Apr 2, 2015

Removed the tank it is solid, checked the seal on the sending unit, good connections fuel connections good.

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Magnum PD · Apr 2, 2015

Air filter? LOL

lincolnlocker · Apr 2, 2015

Powerstroker91 said:
Removed the tank it is solid, checked the seal on the sending unit, good connections fuel connections good.

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how old is the airfilter? if absolutely nothing has changed then its not breathing right, has drive pressure leaks, or just flat out got bad fuel..

live life full throttle

Powerstroker91 · Apr 2, 2015

The air filters a couple years old its a cat reusable i just blow air in it from the inside and clean it probably time for a new one.

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lincolnlocker · Apr 2, 2015

Powerstroker91 said:
The air filters a couple years old its a cat reusable i just blow air in it from the inside and clean it probably time for a new one.

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id start there and check for drive pressure leaks!!

live life full throttle

wildbill963258 · Apr 2, 2015

also how long has it been since you replaced your fuel filter?

Powerstroker91 · Apr 2, 2015

Just replaced it a week ago

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Magnum PD · Apr 2, 2015

Are your 4x4 hubs unlocked?

We recommend using the 6637 air intake on this site

Arisley · Apr 2, 2015

Pull the intake off the turbo. Check out what the fins look like.

lincolnlocker · Apr 2, 2015

Arisley said:
Pull the intake off the turbo. Check out what the fins look like.

thats good info too but if this is something that just all of a sudden started then i would lean towards a drive pressure leak..

live life full throttle

Powerstroker91 · Apr 2, 2015

The company i work for gives me filters if i need em, so i get the cat air filters for free! Cant beat it. Turbo fins are like new. Hubs are unlocked.

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ghostriderblk · Apr 2, 2015

Powerstroker91 said:
Yeah i got auto enginuity but im not seeing anything out of the ordinary. Diesel fuel seems good. No running issues, starts with ease in the coldest weather here in PA, idles fine, runs perfect, doesnt have a tick.

I'm in Bethlehem PA and the winter here has put a tole on my 140k 7.3 I moved from Florida so it's not used to it. My milage has dropped as well. I have 12.5 v at start up and 14.5 running so everything should be getting good voltage. I have exact same mods minus inj and Trans. my eps is clogged but I don't think I'll loose 5 mpgs from that. I replaced a fuel pump and hpop outside in January it sucked. Put a scanner on it see what your sensors say maybe a faulty sensor ?

Powerstroker91 · Apr 2, 2015

I got nothing on ae... It runs like a top its just it doesnt seem to be getting the fuel milage it use to. My ole e99 6speed 7.3 with 5 bad injectors gets better fuel mileage lol. I still cant believe that thing still fires up... It runs like **** till warm but it runs lol

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