Trucknut661
New member
brakes are good. I'm assuming it has to be the EBP sensor or tube or both. I found soot around it and no records of it being replaced in 216k miles. Taking it to my buddy's dad shop tomorrow so I'll know exactly what it is
Poor fuel mileage
- Thread starter Trucknut661
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IdahoF350
New member
Just resealed the up pipes on my E99, pitched the non-compressible junk 8194 Fel Pro donuts everyone raved about that leaked like crazy, and passed on the graphite Mahle/Victor F17250 donuts in favor of a pristine set of used Ford seals. Cleaned up the pipes really nicely, replaced the drivers side with a shortened L99 pipe, the passenger pipes are not even remotely similar angles, so I just dressed it nicely and ran with it for now.
What an effing difference in spool up and power. If the throttle response is sluggish, chances are good you've got leaking up pipes. And if you do, you're using more throttle, and that's how you're managing the lousy fuel mileage. I went from 19mpg tuned with the stock turbo on 285/75-16s with 3.73s to 16mpg lifted on 35s, to 15mpg with the D66 (and apparently a small up pipe leak) to 13mpg when I installed the 37s to 12mpg, and then 11mpg at which point I snugged up the flanges best I could, back to 13mpg. All the while, EGTs were getting harder to manage, power was fading, and throttle response was becoming more sluggish. EGTs are down where they belong again, throttle response is snappy, and the turbo starts to spool at 1300rpm instead of 2000rpm, I expect the next tank will see an improvement back into the 15+mpg range once I lay off the skinny pedal.
Now, I did have an '01 F550 with a service bed that weighed in at close to 22k at my last job that had 285k on it, with 4.88s and 225-70-19.5s thats like driving a truck with 3.73 everywhere with the overdrive turned off, and those 285k miles were equivalent to close to 400k because of the rpm that old girl turned everywhere she went going 68-70mph. I did a turbo overhaul, bellowed pipes, new IC boots, and finally injectors on that truck because it got to the point it would barely start. It went from 8mpg to 12mpg, power was way better, and you didn't have to drive it nearly as hard after all the freshening up.
So depending on miles, prior service, and possibly older repairs you're not aware of, you may have some work to do to get this dialed in, but unless its just tired or wounded you should be able to get into the 13-15 range mentioned earlier, maybe a little better still, even with the aerodynamics of a brick lifted 10" on 40s.
What an effing difference in spool up and power. If the throttle response is sluggish, chances are good you've got leaking up pipes. And if you do, you're using more throttle, and that's how you're managing the lousy fuel mileage. I went from 19mpg tuned with the stock turbo on 285/75-16s with 3.73s to 16mpg lifted on 35s, to 15mpg with the D66 (and apparently a small up pipe leak) to 13mpg when I installed the 37s to 12mpg, and then 11mpg at which point I snugged up the flanges best I could, back to 13mpg. All the while, EGTs were getting harder to manage, power was fading, and throttle response was becoming more sluggish. EGTs are down where they belong again, throttle response is snappy, and the turbo starts to spool at 1300rpm instead of 2000rpm, I expect the next tank will see an improvement back into the 15+mpg range once I lay off the skinny pedal.
Now, I did have an '01 F550 with a service bed that weighed in at close to 22k at my last job that had 285k on it, with 4.88s and 225-70-19.5s thats like driving a truck with 3.73 everywhere with the overdrive turned off, and those 285k miles were equivalent to close to 400k because of the rpm that old girl turned everywhere she went going 68-70mph. I did a turbo overhaul, bellowed pipes, new IC boots, and finally injectors on that truck because it got to the point it would barely start. It went from 8mpg to 12mpg, power was way better, and you didn't have to drive it nearly as hard after all the freshening up.
So depending on miles, prior service, and possibly older repairs you're not aware of, you may have some work to do to get this dialed in, but unless its just tired or wounded you should be able to get into the 13-15 range mentioned earlier, maybe a little better still, even with the aerodynamics of a brick lifted 10" on 40s.
Trucknut661
New member
So my truck is fine. Nothing wrong with it. I got a hold of the previous owner to see who calibrated everything for him. Turns out the guy never calibrated it properly. When the computer got hooked up to the OBD 2 port it came back with stock information. So my odometer isn't correct and that's the problem. Going to have to go on a fairly long drive to hand calculate mileage until I can get my hydra chip and have them do a customs tune with all the mods I have. Then that will set my odometer right
79jasper
Active member
With the SD, can't you use forscan to adjust tire size?
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Sent from my SM-G892A using Tapatalk
Arisley
Moderator
A tune will not correct the speedo.
Trucknut661
New member
My buddy's dad tried using his program at the shop and ford tried as well but they said because the tires are 40's it won't let them adjust it. I guess they have a certain size they can go up to for adjustments on 7.3's. They said if it was a 6.0 it wouldn't be a problem since it has all the electronics. So I called a diesel performance shop that specializes in tunes and they said they would have to build me a custom chip which has all my mods, tire size and gearing factored in to the chip so when I hook it up everything will read right. They suggested php hydra chip. I am not trying to adjust the speedo, I'm trying to adjust my odometer so I can get my mileage to read right and not have to keep hand calculating.
rusty1161
Member
The speedo and odometer work hand in hand. Chips do not adjust the speedo.
If you can still find one, get a Superlift Truspeed calibrator and wire that thing in.
Rusty
If you can still find one, get a Superlift Truspeed calibrator and wire that thing in.
Rusty
Trucknut661
New member
Gotcha 10/4
PSD POWER007
Member
Give this guy a hand!:clapping:
uncool
New member
If you ever get up to Atascadero, highway 101 after San Luis Obispo, I will plug in with Auto enginuity and we can get your speedo a lot closer than it is now.
Marc
Marc
lariat 7.3
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on the analog odometer trucks the odometer isnt effected by the calibration of the speedo right? i did a test and mine was 5 miles off every 100 miles
Garbage_Mechanic
Member
They have to be connected since one measures distance traveled and the other measures time vs distance traveled. If the distance traveled portion is off, the whole thing is off. The distance measurement portion measures rotations and works off of a calculation of rotation = x distance traveled. I used to calibrate cable drive speedos. How many rev's per measured .10 mile was the key. Still have the clicker and gearbox kits.
Trucknut661
New member
Thanks uncool I appreciate it
