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high egt low mpg

Discussion in '7.3L Powerstroke Diesels' started by nj_m715, Apr 14, 2019.

  1. nj_m715

    nj_m715 government's finest Supporting Member

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    96 psd started acting up. seems to run ok but I noticed increased egt and high fuel consumption
    I estimate that I used about 5 gals to drive 32 miles, I normally get 17.5

    normal driving empty truck with rolling hills egt are 400-800 now I see 400-1050

    new back pressure tube, cleaned sensor last yr
    ebpv delete
    hydra - runs the same with or without tunes
    napa filter
    3" dp 4" diamond exhaust
    all mods are a yr old or more
    no codes on car gauge pro

    my hands are full for the next couple weeks so I don't have much time to tinker
    can you think of any relatively simple things to check before I send it to the shop?
    stuck injector dumping fuel too much fuel?

    I might have time to buzz test tomorrow, not sure if it would show anything

    thanks
     
  2. nj_m715

    nj_m715 government's finest Supporting Member

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    lol, this is why I posted on the IDI side when I was stranded out of state and looking for a fuel bowl.

    talked to my shop, he's busy for 2 weeks, said it sounded like exhaust/ boost leak

    just installed a boost gauge to see, wanted to install one anyway. either the gauge is bad or I'm making no boost

    gauge reads from -1 to +1 psi

    time for soapy water I guess
     
  3. greenskeeper

    greenskeeper Full Access Member

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    15 psi or so is stock boost at WOT

    Assuming you don't have an intercooler being an OBS, sounds like you've got an air blockage going into the turbo (filter?) or blockage in the exhaust (EBPV?)
     
  4. nj_m715

    nj_m715 government's finest Supporting Member

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    I built a pressure adapter, aired up to 15-20psi, found no obvious leaks but my pos boost gauge read 3 psi so my boost might be fine
    I have napa filter, intake side looks ok, ebpv deleted last year

    I'm no modern computerized mechanic, but I'd still guess injector leaking fuel, idk?
    all that extra fuel is going somewhere, it's not on the ground, its not in the crankcase. I think it's going out the exhaust but theres no excess smoke
     
  5. greenskeeper

    greenskeeper Full Access Member

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    Finish the tank and calculate actual fuel mileage. You really need at least 3 tanks to get a good average. Maybe the selector valve is failing and its dumping fuel back into the unused tank?
     
  6. nj_m715

    nj_m715 government's finest Supporting Member

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    I don't drive that, truck sits a week or more at a time. would take a year or more for 3 tanks
    I'm almost down to 1/3 I haven't refilled since the fall that's why I have to estimate by the gauge
    I calculated my 17.5 mpg on a rare road trip last year
    but the unused tank is normally topped off so it should overflow quickly
     
  7. greenskeeper

    greenskeeper Full Access Member

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    So you're trying to compare fuel mileage on a road trip to very short trips, separated by weeks? 10 mpg wouldn't be out of the ordinary for short trips.

    Why worry about fuel mileage if you drive so little?

    Did a varmint make a nest in your intake or exhaust, blocking flow and increasing the EGTs?

    You need to get out and DRIVE your truck, then see what the mpgs are before throwing parts at it, chances are nothing is wrong especially if there is no CEL.

    [​IMG]
     
    Thewespaul and DaveBen like this.
  8. nj_m715

    nj_m715 government's finest Supporting Member

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    So you're trying to compare fuel mileage on a road trip to very short trips, separated by weeks?
    no, I'm just using the info I have available

    10 mpg wouldn't be out of the ordinary for short trips.
    I estimate closer to 5mpg, but whatever.
    I live in the country, it's pretty much all highway driving. there's not much difference going 55 on a county highway or 65 on an interstate.
    there's not much stop and go around here
    I wouldn't expect exactly the same mileage but suddenly there is a noticeable difference

    Why worry about fuel mileage if you drive so little?
    I'm not but something it wrong with the truck, If I was worried about mileage I would buy a vw rabbit

    Did a varmint make a nest in your intake or exhaust, blocking flow and increasing the EGTs?
    maybe, would that smash mpg into the ground?

    You need to get out and DRIVE your truck, then see what the mpgs are before throwing parts at it, chances are nothing is wrong especially if there is no CEL.
    thanks for the advice, I checked for codes, did a boost leak test and asked for ideas. I don't throw parts at problems I prefer trouble shooting to parts changing
     
  9. greenskeeper

    greenskeeper Full Access Member

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    Ok, so drive enough to calculate the actual mileage and go from there instead if estimating fuel consumption.

    Maybe the pump clicked off at your last fillup weeks ago and you never started with a full tank?

    Somebody stealing fuel from your truck?
     
  10. nj_m715

    nj_m715 government's finest Supporting Member

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    I'm from nj, I got locking fuel caps. and if someone can steal fuel while I'm moving down the road at 55, then they deserve to have it
    I didn't start with a full tank, I watched the needle drop from exactly half to about 3/8th while only driving 30 miles
    I have a 39g tank I never see the needle move in 30 miles

    needle movement isn't an exact science but I never observed this behavior before, it's obvious something is going
     
  11. greenskeeper

    greenskeeper Full Access Member

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    Ok I give up...where’s the hidden camera on this joke of a thread?
     
  12. nj_m715

    nj_m715 government's finest Supporting Member

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    bro, no one is stealing my fuel, no squirrels live in my exhaust and my second tank is not overflowing
    the truck is consuming more and running higher egt's

    I don't need to burn through 3 tanks to know my fuel consumption and egt's doubled
     
  13. nj_m715

    nj_m715 government's finest Supporting Member

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    decided to throw parts at it, replaced the turbo boots and resealed the Y pipe
    running much better now, normal egt, got 15 mpg on a 200 mile trip
     

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