History:
1997 Ford F350, DRW, 4X4, 5 speed, 4:10 rear. I bought the truck from a small dealer. It was in a fleet division. After I bought it, I noticed it was weak when I pulled a trailer.

Modifications:
I cut the exhaust out, put a 3" down pipe and installed a superchips tuner. It was still low on power, and sucking fuel, so I took it to a ford dealer. They replaced 2 injectors and cleaned all of them. It runs better, but still is weak.

Problems:
Poor fuel mileage when pulling. I am lucky to get 10 when towing only 8000 total lbs. It is worse on the stock setting. My accelerator seems weird. Usually, the farther you push the pedal down, the more fuel it will give. Not mine, the first 1" of travel and that is as much as it will give. I can mash it to the floor, but it will not accelerate any quicker. Of course it will go faster in the end, but as far as it getting more power the farther I push it, forget it. Boost seems low. At 2500 RPM 12psi. At 3000 RPM 18psi. I have it set on the highest setting as well. Very little smoke is blown from exhaust, and I am running Cetane booster. My father in laws truck runs as good as mine, and it is bone stock. I should be runnig over 100HP hotter than his. EGT gets no hotter than 1000 degree. It runs the same temp and boost on the stock setting as well.

Question:
Is my boost low on the turbo? Is my accelerator messed up and causing all the problems? Is it low on fuel pressure?

 

10mpg with the 4:10 rear pullin 8k sounds about right. The superchips is a POS tuner btw, should have gone SCT. The superchips will destroy your tranny and builds up a lot of pressure in your engine. 18psi at 3,000 RPM is low though. May have sticky turbo veins.....do a search on that, you'll find a lot of info.

 

Friend of mine has a '99 7.3L PSD. He recently had to replace the pipes that run from the exhaust manifolds up to the turbo. Both were leaking badly which equals low boost. Night and day difference, his truck is stock and replacing the pipes/seals really woke it back up.

I may be way off base, Just wanted to throw that out there...

T. J.

 

superchips was the most highly suggested to me by a diesel shop in town. when you say SCT, what do you mean? If I am going to have issues with the tranny, I will swap it out. I only paid $150 for it on ebay. I tried to search the net for what the boost pressure is suppose to be, but I can't find anything. It puts me onto these forums to get the answer. My local dealer couldn't tell me either. I hope it isn't just a dog.

My dad gets 15mpg with his 96, loaded and empty. He pulls around 12000 on a regular bases, and sometimes 24000. Now, obviously he doesn't get as good pulling 24000, but he does get 15 at 12000. I would be happy with 12. I get 15 empty. I think the turbo, or accelerator position sensor is bad, but I am not a mechanic. I really don't think it is fuel pump related, but you never know.

 

Superchips is crappy. For the 7.3l many guys run the DP tuners. SCT is a great tuner.

 

You're complaining about getting only 10 MPG when pulling 8000 pounds?

Sheesh.

 

call matt at spartan diesel out of north carolina hey sells sct tuners and makes the custom programs for them let him know what stuff you have on your truck and what you mainly use it for and he will for sure get you hooked up..... they are awesome there.

 

I am not sure how much boost the 97 trucks make they have a smaller turbo than the 99.5 and up but check all your boots for the turbo and IC and check your exhaust up pipes for leaks.



You will get better help in the 94.5 to 97 section of the forum here is the link.
https://www.ford-trucks.com/forums/forum170/

 

for a dually with 4.10s about 15 mpg empty 16.5 if you drive slow if everything is great is all you should get
loaded 10 mpg ain't bad depending on speed and type of trailer,with enclosed trailer mine don't care if you got one BB or a full load it gets the same
if you father gets 15 mpg towing 12k it's one in a million
as stated the super chips ain't much you may get 50 hp you can get a good chip here
http://www.dp-tuner.com/

 

10mpg sucks! Around here, 12 is the average. My dad gets better, even my father in law gets 12-13, 18 empty, and it is an automatic transmission to boot.

 

Do you have a bed cover?

When I tow my trailer (pictured, 28 foot car hauler) with my tonneau cover my mileage drops to 7.5-8 MPG. If I take the cover off my mileage is 10-10.5 MPG.

 

nope. i have a flatbed.

 

only way to get any fuel milage is to keep it under 2000 RPM kinda hard to do with
4.10s
I think someone already mentioned to check up pipes for leaks and intake boots

 

Did you mean that the other way around? Do you get worse with the cover on?

Not picking at you, just curious. I thought you would get better mileage with the cover on, being that it would deflect the air out of the bed...

I never really noticed a difference in my truck with the cover on/off, but i do mostly city driving....

thanks

 

Redford found that with his cover "on" while towing it caused the air to rush right into the front of the trailer and decreased fuel mileage. The cover helps a bit when not towing, but actually hurt his mileage while towing. I assume in the city you are not towing a load with the cover on but it wouldn't make much difference at city speeds.